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Blood Sweat Tears and Grease => Projects => Cafe Racers => Topic started by: cb250nproject on Apr 16, 2017, 01:57:48

Title: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Apr 16, 2017, 01:57:48
Hey All,

For a long time I have gained insight and answers by reading through the various articles here so I thought I would post a build thread here.

About 9 months ago I purchased a 1982 DOHC CB 750 F2, pretty sure it was an ex police bike as it had the charger wired in the paniers and the fact that the ex motorcycle cop that sold it to me told me it was pretty much confirmed my suspicions.

It was pretty tidy and for $3400 I couldnt pass it up, other than having a flat battery mechanically it was fine started it up and rode it home not a problem

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I already had a fair idea of some of the modifications I wanted to do in this build, one was the GSXR 750 front end upgrade, upgrade the exhaust, rear shocks, wheels, cam, carbs, rear hoop installation and the rest I found out as i went.

First of all i removed all of the fairing to see what lay beneath



Title: Re: 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Apr 16, 2017, 02:22:10
So after removing all of the fairing, airbox and fuel tank I noted the original rear shock were starting to show signs of rust as you would expect from a bike 30+ years but overall everything was looking pretty good.

The wiring loom that resembled an anaconda was something that i would look at slimming down at a later date/ the wiring never was pretty on these old Hondas (http://)

So I got onto Ebay and started hunting for a donor front end, it took a little while to find a set but i ended up getting a 2008 GSXR 750 front end that had the top and bottom tripple and axle for about $980

Next on the list was rims after looking around I decided to go with the Cognito Moto conversion hub, I picked up a rear spoked hub from and earlier model 750 that still had rear disc. both front and rear hubs were 42 spokes

The next challenge was to find rims to suit, I wanted to try and get a slightly fatter rear tyre on the back without blowing the budget out going crazy with the rims. For the front i ended up getting a 17" x 2.5 Morad brand new by the time i got it freighted here it was about $270, luckily i scored a second hand BMW rim that was 17" x 3.5 not as wide as i was hoping but for $42 i couldnt say no.

Title: Re: 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Apr 16, 2017, 02:45:26
So i sent the front hub of to get anodised as I found a place that could do it pretty cheap at home, while i was doing that I sent the rims away to get hydro blasted and powdercoated gold.

Originally I had planned for the bike to be all black except for the rims being gold with gold decals on the tank, but as it ended up turning out that wasnt the way it was going to be.

It took me a while to find the exact gold that I wanted I came across a company Prismatic Powders who offered a few different variants of gold I ordered colour swatches but after a few weeks didnt think they were going to arrive so I bit the bullet and ordered a a powder called prismatic gold unfortunately just after I received the powder the swatches arrived and I quickly realized that wasnt the colour I wanted, so I went with another colour Goldtastic which ended up turning out spot on

but i ended up going with a powder from prismatic powders called goldtastic, 
Title: Re: 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Apr 16, 2017, 04:03:03
Before starting the build i had done a bit of research and knew that the triple stem would need to be changed there seemed to be two options get a Cognito Moto one or look at fabrication one up, luckily for me the old man has a lathe and is always up for a challenge so we made some measurements and guesstimations

The bearings and races also need to be changed I found a conversion table online   

http://www.allballsracing.com/index.php/forkconversion

After looking here I went into a bearing shop and simply ordered the bearings i needed for less than half the price it was going to cost me to order them. The bottom races are fairly similar but the top race is thinner than the original Ive attached a photo so you can see for comparison

First I grinded off the stops from the bottom triple, then we pressed the original stem out from memory there was some sort of retaining pin and I think we heated it up a little, she was fairly stubborn but eventually came out in the press.

Next we measured the CB 750 stem against the GSXR stem to work out the difference then went to work on the lathe, i wont lie there were a few attempts before we got it right, you can see the original stem up top with the two failed attempts and the final in the lower triple

To press it in we put the stem in the freezer and i think we warmed up the lower triple before pressing it back in
Title: Re: 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Apr 16, 2017, 04:27:51
After the stem had been pressed in it was time to give it a test run.

Unfortuntely we miscalculated by about 4 mm so the thread of the stem was a few threads shy for the nut to go on properly, luckily the old man had anticipated it and left a lttle extra shoulder on the bottom of the stem so we pressed it out again and put it back on the lathe repeated the process and she came up sweet.

Im still to install new stops on the bottom of the triple.

When building this bike there was one underpining principle functionality over form, while having an asthetically pleasing ride was what I am hoping for safe comfortable rideability was what I was going for. so as much as low clip ons would look cool i ended up ordering some woodcraft 2.5" risers ( yet to arrive in the post )



 

 
Title: Re: 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Apr 16, 2017, 04:42:25
When I ordered the Cognito Moto conversion hub i opted to get all the spacers and bearings which we had to press in after I had the Hub anodised, just a FYI and something I learned by fu$king up unless it CNC billet aluminum anodising wont come out so good so when i went to get the rear hub anodised it ended up coming out a greyish colour (booo) it ended up getting sprayed out of a can.

For the rear hub i simply took the old bearings into the bearing shop and reordered the same.

After the front hub bearings had been pressed in i did a little mock up as we had the GSXR front end in the garage, and as advertised it fit like a glove
Title: Re: 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Apr 16, 2017, 05:01:03
Now that the Hubs were in order and the front end conversion was completed it was time to get the Hubs laced up, it actually took a little bit of searching to find someone to do it, finally i came across Bruce at Fastline Spokes

I had ordered some new front brake discs that arrived so i fitted them up then took the rims and Hubs to Bruce to be laced up and trued

While the hubs were away getting laced I figured it was time to look at installing the tail hoop. I had one in the garage that I had purchased for a previous build that i ended up not using.

First we worked out where the cuts were to go using the measure, measure and then measure again before cutting rule, after the cuts were made we used some smaller steel tube inserted into the frame as a lug. We then cut the hoop down to the required sized and welded it in place.

after looking at it ive realised that the hoop needs to be bent down about an inch this will be a little bit of an operation :/ and one yet to be done

the rims came back so i thought I'd just mock it up with the wheels just because there was nothing else i could do at the time
Title: Re: 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Apr 16, 2017, 05:40:53
I ordered myself a Delvic 4 into 1 exhaust, then headed down to Pablos and got some tread onto the wheels ended up getting a 110 / 70 front and 150 / 60 Pirelli Diablo Rossi II.

at the same time I ended up finding some Hagons rear shocks on ebay for $150 so i snaped them up and mocked it all up to see how the bike would look.

i removed the wiring loom and original foot pegs, I ended up getting an Ultima wiring loom but that will be one of the last things to get installed

she sits pretty low :/ we will have to see how she goes i think i can get a few more mm out of pushing thr forks all the way through the triples

900 cams to come

 
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Apr 21, 2017, 21:38:50
Some stuff arrived in the mail, pity I'm at work

Ultima wiring loom

Woodcraft 2.5" risers

CBR 600 F2 coils
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: Tim on Apr 21, 2017, 22:33:37
Wow!  Thanks for posting up the build detail - is this where you are now or is the bike complete?
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Apr 21, 2017, 23:03:46
Thanks Tim (my apologies for typo text on the phones starting to get a little too small to read these days), this is where i am now, working away for the next 5 weeks so once i get back home i will instal the cb 900 cam and hopefully get the valve clearances sorted, then the handle bars just to get an idea of the riding position.. then start to dream up the seat and tail end maybe look at making up some brackets to mount the rearsets.

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Apr 28, 2017, 02:06:03
I want to install an oil cooler can anyone point me in the direction of a supplier of a kit ??
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: spotty on Apr 28, 2017, 02:18:21
looking good, can't think of a finer thing to do to an old cop bike (who knows it may have been one of the ones used to nick me for something in days gone by...)

didn't CB1100's (and maybe some 900's) have a cooler stock? maybe search the info and see if any of the wreckers have got one somewhere.
 
theres plenty of a/market stuff out there for the actual coolers but getting the fittings, the wreckers might be your only option

are you using the old wheels? I might be interested in the front for my CB750K8 which already has CB900 forks but its going to be easier to use the 900 wheel and discs than try and get decent brakes and such to work with the stock wire wheel

where in (not so ) sunny Melbourne are you? i'm in Kalorama,  right on top of mount Dandenong so I get one of the best trips home every night after work, straight up the tourist rd
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Apr 29, 2017, 07:31:05
Sweet spot to live in, mad roads up there I use to ride the black spur back on my little RGV 250 good times.

This is the front wheel I removed was going to off load it for $125 with discs there should be plenty on them but i wont be able to get the calipers on them until i come home in June. Im on the west side in the bronx of sunshine west  :-\

Got any photos of your build ? Im always interested in how peeps go about their builds

Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 04, 2017, 05:40:19
ok so finally came home and tried to install the cb 900f cams (http://)

had a few mishaps along the way :/ two of the cam journal bolt broke off, a common occurance but none the less inconvenient.

has to drill and tap out new threads then when i reinstalled the bolts I added a little bit of antisieze  and then worked out the torque setting for wet bolts (different to the dry torque settings)

I was also unable to use the sprocket from the 750 cam which I tried to do because the sprocket was chamfered on the 900 cam and I was unsure how it would effect things. but the decision was ade easy when i realised it wasnt interchangeable.

then had to reshim to get the valve clearances right still need to find some 260 and 265 shims that will be tomorrows mission hopefully and ill put on the woodcraft riser clip ons on.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 06, 2017, 05:23:00
(https://uploads.tapatalk-cdn.com/20170606/5c7501c25a2d0b4648f902259d4c2b36.jpg)(https://uploads.tapatalk-cdn.com/20170606/46ee99b48972c1a93d5f5dbf7963ce52.jpg)

Went out and got studs to mount the rear disc that I had. Now just to make a spacer for the left side of the wheel.

Also got a chance to fit the 3" riser clip ons, it doesn't look as trick as low clip ons but it sure is comfortable. Tomorrow I'm hoping to get a start on the tail end see how that goes


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: brad black on Jun 08, 2017, 08:24:17
man, that rear disc is huge.  you need to cut it down and fit a smaller caliper.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: spotty on Jun 08, 2017, 21:13:02
man, that rear disc is huge.  you need to cut it down and fit a smaller caliper.

i'd leave the disc that size but replace with a matching one to the fronts or even just get it drilled so it looks similar, the solidness looks kind of wrong with the front drilled ones, and get rid of the black plastic thingy off the back of the caliper or put a matching 4 piston nissin on, the more brakes the better.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: CrabsAndCylinders on Jun 09, 2017, 19:33:37
Yeah, I think that black plastic thingy is just to keep water from getting flicked upward.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 09, 2017, 21:05:59
I agree the disc does look odd, would it be cheaper to get it drilled? or just buy a brand new disc?

Also im trying to work out exactly what model of cb 750 had the 6 stud bolt pattern for mounting that disc, the other ones I had were all a 5 stud bolt pattern, that was off the original wheel that came off. dont want to oreder the wrong one.. again

Given how little the rear brake does i dont think I will go to the trouble of putting a nissin caliper on, I have ordered a kit and was going to strip down and refurbish the original caliper. I think the brake upgrade that came with the GSXR fork conversion will still make it like night and day.. thats wat I'm hoping anyway
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 13, 2017, 05:07:23
(https://uploads.tapatalk-cdn.com/20170613/99b6eeb9cd8982ee07c3844afb55e796.jpg) so I'm mucking around with the tail part of the bike trying to get a rough idea of how it's all going to come together.
I've decided to add small side fairings to kind of finish it off... you're going to have to imagine it connects with the tail section and covers over the rear hoop...(https://uploads.tapatalk-cdn.com/20170613/d9adc46170b4dda01d7c16af090032e4.jpg)
It just looks kind of unfinished without the side fairing.

Although I've got all the gear to fibreglass it up I think I need to do a little more r & d on how best to incorporate the side fairings and also how the fairing is going to marry to the frame.




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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Jun 14, 2017, 08:15:54
Really cool build! Following along for sure. I have a 900F that I plan on giving a similar treatment, although on a bit more of a budget so will be using CBR wheels instead of spoked ones and a 919 RWU fork. Nice to see the Delkevic exhaust on an F build, I've been eyeing that same one and it looks good! I like the way you're going with the rear!

Ground clearance seems like it could be a problem? Have you done the rake/trail calculations? From what I understand one drawback of the GSXR front end is the small offset in those triples that could lead to really low trail numbers. I'm no suspension expert, but that's what I've been able to gather. You might be able to kill two birds with one stone and get custom triples from Cognito that are raised/winged (to gain some ground clearance) and with something like a 45mm offset?

Btw, what is the total length of those forks?

Good luck with the build!
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 15, 2017, 02:26:35
Hey Lights out

GSXR forks are 720mm with 17" rim the originals are 780mm with 19" rims, when I was looking into it i noted that CM offer a triple converion stem and bearing set, it ended up being a lot cheaper to turn one up on the lathe and grab the required bearings from a bearing shop. because CM offered the conversion stem i assumed (making an ASS out of U and Me) that it was all good and didnt check (rookie error).

I do intend to put a steering dampner on after a friend from MCR came unstuck on his tricked out cb 750. Im actullay only really concerned with the clearance or lack thereof :/ the Delvic pipes look sick but Im worried on a sweeping right hand corner it will be ground away. If worse comes to worse Dad just purchased a mill so maybe try to turn up an new triple if required

At the moment im trying to prepare the mould for the tail section I'm nearly happy with the shape I'll lay mesh over the mould before I pour the resin hopefully give it some more strength

see how we go, unfortunately my breaks nearly over :/ so the build will go on hold for 6 weeks booo

Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Jun 15, 2017, 05:33:59
The CBR900RR forks I'll be using are 732mm and I'll be using a 17" CBR/VFR front wheel (the Fireblade had a 16" but that's way too small). My 900F had the 18" front, but I assume frame geometry wasn't changed when they went to 18" from earlier years 19" so that probably wont't help me, I'll be in just 12mm better situation than you  ;D
With the CBR forks the original stem can be used, since Honda has been kind enough to use identical stems for a long time - so no conversion stem/lathe work or special bearings needed. Doesn't help the height or offset issue though :)

Darren Beggs (who built these (http://www.darrenbeggcustoms.com/?page_id=23) beasts) uses winged top triples to regain some ground clearance when using shorter forks. Here (http://photobucket.com/gallery/http://s33.photobucket.com/user/dbegg/media/RED%20CB1100F/DSCN2957.jpg.html) are some pics of what they look like.

Looking forward to progress on the seat/tail. Where will you be putting the battery? Will a small one fit under the hump?
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 15, 2017, 07:11:27
Really cool build! Following along for sure. I have a 900F that I plan on giving a similar treatment, although on a bit more of a budget so will be using CBR wheels instead of spoked ones and a 919 RWU fork. Nice to see the Delkevic exhaust on an F build, I've been eyeing that same one and it looks good! I like the way you're going with the rear!

Ground clearance seems like it could be a problem? Have you done the rake/trail calculations? From what I understand one drawback of the GSXR front end is the small offset in those triples that could lead to really low trail numbers. I'm no suspension expert, but that's what I've been able to gather. You might be able to kill two birds with one stone and get custom triples from Cognito that are raised/winged (to gain some ground clearance) and with something like a 45mm offset?

Btw, what is the total length of those forks?

Good luck with the build!

The forks are about 720mm long with 17" rim as opposed to the original 780mm with a 19" rim  that was on it.

I'm not too sure of how the numbers work out, we fabricated a new triple stem and pressed it into the original GSXR triple, cognito moto also offer a replacement triple stem also but it was a lot cheaper to turn it up on the lathe ourselves.

I'll have to see what she rides like definitely need a steering dampener after talking to a mate from MCR who came off his cb750 from tank slapping, although his was a monster bored out and Dyno tuned.

If worse comes to worse Dad just got a mill (https://uploads.tapatalk-cdn.com/20170615/1bf5c55b88e76d849ed35efa6d3191fd.jpg)
Which I reckon he is dying to use, will definitely be fabricating the rear set brackets with that.

Managed to snap up a few more goodies on line (https://uploads.tapatalk-cdn.com/20170615/3740af7986df27fa5dfca59d4b96537a.png)

So now Frankenhonda II will have some lungs

Today I've been trying to mould the seat pan up ready to

Those are some trick beasts.

I think once I put the fibreglass on the tail section and get that sorted I will make up a seat pan also. I was unable to put the resin and glass on because I had nothing to use as a release agent...poorly prepared.

There's some kick ass small batteries but I'm unsure which ones are best.

Just got some of these too (https://uploads.tapatalk-cdn.com/20170615/283ea4b4e16b3b2812dea1a77af6cb80.png) but I don't think they will arrive before I leave.

You'll have to show us some shots of your build


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 15, 2017, 22:33:27
Today I fibreglassed the tail section.

First I made a mould basically I used some foam for the tail section and cardboard for the seat pan
(https://uploads.tapatalk-cdn.com/20170616/4ac580705a3a85b58bb8949eb1a9cf8e.jpg)

Then i taped the lot up so it wouldn't stick and also the tape give a much smoother finish than my bread knife made cuts.
(https://uploads.tapatalk-cdn.com/20170616/42acfc23923f4c135d2572892227eaf6.jpg)

I then put mesh over my mould to give the fibreglass a little more rigidity, but unfortunately I did not put wax on the tape as a releasing agent. So after getting it all nice and tied into place I removed it,waxed it up,then reinstalling the mesh
(https://uploads.tapatalk-cdn.com/20170616/b6f7cc7154b70c28b4e5837d6f90047a.jpg)

Then I cut out my sheets of fibreglass I used two different kinds one that is a cloth and the other a fibreglass matting. I think the matting is stronger but the cloth gives a nicer finish (https://uploads.tapatalk-cdn.com/20170616/25b09e11e01944f8cc1874bd0d3e1a67.jpg)

Then I used a plastic sheet to cover the rest of the bike (https://uploads.tapatalk-cdn.com/20170616/4d14df9a8c6b93431f363b10bb2312de.jpg)

Then lay the resin on and fibreglass (https://uploads.tapatalk-cdn.com/20170616/89d78121df9ff9e61eee590a36652efc.jpg)(https://uploads.tapatalk-cdn.com/20170616/a0265acf3322c8b577368630ad1c294a.jpg)

Now to wait for it to dry



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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Jun 16, 2017, 05:00:58
Damn, those CRs are sexy! Fibreglass work looks good, giving me lots of good ideas here :)

I will start a thread once my build is properly underway. At the moment I'm planning and gathering parts... and (slowly) working on a GS550 build.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 16, 2017, 05:48:00
We'll progress was slow and I'm all out of filler

(https://uploads.tapatalk-cdn.com/20170616/121219f5aa0ec62ecb9140c890ff8f56.jpg)

I think I have the shape right tomorrow I'll go and get more filler and some more sand paper

(https://uploads.tapatalk-cdn.com/20170616/47a1bd2bddce905fafbe64a33b2c78a3.jpg)
(https://uploads.tapatalk-cdn.com/20170616/a5eb8e7140ec889c94f046bc91426d04.jpg)(https://uploads.tapatalk-cdn.com/20170616/f511790ec2758ab9b6328775b74c4cac.jpg)(https://uploads.tapatalk-cdn.com/20170616/faf831ace46667364f5ddd6aca3e2f62.jpg)
(https://uploads.tapatalk-cdn.com/20170616/fa8cabf5ed1d00b96f7ff8b277ebd529.jpg)(https://uploads.tapatalk-cdn.com/20170616/110829dc5d8d9436179bee36434aeb6f.jpg)

Let's see how many runs I can get on the board tomorrow


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 17, 2017, 06:39:15
Ok so I cut it out and she's a little rough (glass half full optimism)

She still needs a lot of work and I need to get a contour gauge to help me get the shaping spot on
(https://uploads.tapatalk-cdn.com/20170617/bd60ed25afc35a18e2524b3f158b432a.png) hopefully this tool allows me to get the clean finish I want as paint only highlights your imperfections.

(https://uploads.tapatalk-cdn.com/20170617/e5bc4f3d9ec3a24b58890e809db44294.jpg)(https://uploads.tapatalk-cdn.com/20170617/03dbcdd1fdccb9a4647ab650d5d80427.jpg)

You can see where I cut too much off on the front left near the tank I'm not happy with that line and need to fix it up (https://uploads.tapatalk-cdn.com/20170617/9aea7705859087e9232d8f628c80e051.jpg)

(https://uploads.tapatalk-cdn.com/20170617/bd0e0610ba53c08a4bbb713ef8564686.jpg)(https://uploads.tapatalk-cdn.com/20170617/0f6bbd982fc73f16f1325036df5a4b15.jpg)(https://uploads.tapatalk-cdn.com/20170617/1a6f9b8cbed3d6a18735d8cbb711bc80.jpg)(https://uploads.tapatalk-cdn.com/20170617/69e2e18d7b298720a65771b9893a7fbe.jpg)

So that's where I'm at it's a long way from where I want to be but hopefully I can make it work


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: brad black on Jun 17, 2017, 10:12:10
I agree the disc does look odd, would it be cheaper to get it drilled? or just buy a brand new disc?

Also im trying to work out exactly what model of cb 750 had the 6 stud bolt pattern for mounting that disc, the other ones I had were all a 5 stud bolt pattern, that was off the original wheel that came off. dont want to oreder the wrong one.. again

Given how little the rear brake does i dont think I will go to the trouble of putting a nissin caliper on, I have ordered a kit and was going to strip down and refurbish the original caliper. I think the brake upgrade that came with the GSXR fork conversion will still make it like night and day.. thats wat I'm hoping anyway

you could ask max at planet discs.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 18, 2017, 03:31:35
you could ask max at planet discs.

Cheers Brad I'll probably touch base with them next break


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 18, 2017, 03:43:35
So I'm trying to take a more measured approach.

So I drew up a centre line and a few other points of reference (https://uploads.tapatalk-cdn.com/20170618/ca6117caa643ed022b98d3219cdbe2a3.jpg)

As you can see it took me a couple of attempts to get it where I wanted to (https://uploads.tapatalk-cdn.com/20170618/092debff9f39b99729012e389c1a9ec4.jpg)(https://uploads.tapatalk-cdn.com/20170618/14db4b82f11ebc3b25f5fdf038420506.jpg)

Once the lines were drawn I cut it all as close to the desired shape as I could (https://uploads.tapatalk-cdn.com/20170618/b35233b7e0c5d43f59ef08f854b47f7f.jpg)

Next thing I did was go to work on the left hand side of the seat pan didn't mould to the chassis rail it was bowing out a little in two spots and was doing my head in so I cut them out the redid the left side (https://uploads.tapatalk-cdn.com/20170618/467c8f755dea1e75d98af0f46da4c78d.jpg)
(https://uploads.tapatalk-cdn.com/20170618/3ba5a8744cc9b23dbe1dd98d7df163a1.jpg)

You probably can't see the difference in the before and after but it follows the contour of the tail around much better.

Once the resin dries I may have to build it up wit a few more pieces of fibreglass just to get it sweet.

In addition there are a few spots that will need to be filled in and levelled out then I'll look at cutting the slot in for the rear tail light LEd strip and I'll have to weld a support bracket for the hump in the tail




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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: Popeye SXM on Jun 18, 2017, 21:53:20
Great bike! The joy of fiberglass is you can keep adding or removing it until you get the shape you want. You just need time and motivation!!!!! For me that rear disc is spoiling the good looks, drilling some holes to match the front ones might help. 
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 19, 2017, 07:56:16
Great bike! The joy of fiberglass is you can keep adding or removing it until you get the shape you want. You just need time and motivation!!!!! For me that rear disc is spoiling the good looks, drilling some holes to match the front ones might help.
I agree wholeheartedly the disc needs to be drilled. I'm away at work now for the next six weeks but once i return ill look at going somewhere to get someone to drill it out, my seal kit for the rear caliper came in the mail today (https://uploads.tapatalk-cdn.com/20170619/017edb31e3ccd3aba47be1faeb0c8d4c.jpg) so i will strip it down repaint it and refurbish it will be a good opportunity to take the disc of and sent it away.

Still have a few other things to nut out now also kike the speedo i had a cable one left over from a previous build but i just realised with the CM hub and spacers i used there is no room for a speedo, so ill have to find some other option with the guages less is more for me small and unobtrusive. Guess ill be scouring the net for options while im at work.

The fiberglass depending on how the ocd is could take longer than anticipated 😕 but it was never meant to be easy, honestly i wish i was an accomplished welder steel seat pans and tails look trick, but unfortunately thats a skill im yet to master so fiberglass it is

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Jun 20, 2017, 06:02:09
Fiberglass work looks really good in the pictures at least!

Don't recall where that rear disc was from, but some (old Hondas) are apparently really hardened so get some good drill bits :)

Re speedo, aftermarket ones like Koso use a magnetic sensor you mount to the one of the brake caliper nuts. That's a clean and minimal solution. Believe they read the tach from the coils as well so that would eliminate the tach cable from the valve cover as a bonus.

...or I've seen some get a sensor from e.g an F3 CBR which reads from the front sprocket. That would require a custom machined or at least modified sprocket cover for mounting though. Google 'dons cup of gold' for a build with that solution.


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 20, 2017, 07:25:11
Lol good from a far but far from good, it will need some TLC when im home next.
Those koso speedos look pretty trick have you used them?

Today the CR carbs arrived in the post today 😆 pretty happy about that, now im just waiting on some shims so i can finish the valve clearances, reseal the engine and give it a good glean up... then onto wiring not ny Forte at all.

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Jun 20, 2017, 07:33:04
Haven't used the Kosos myself, but only heard good things. Will probably be going with them when I get going with my build. Seems like a quality brand. I believe Acewell uses similar setup too.

Remember to set the valve clearances to .005-.006, not down to .002 as the FSM says. At least that seems to be the collective wisdom of the 1100f.net forum :) Too tight especially on the exhaust side risks burning the valves.


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: brad black on Jun 20, 2017, 09:09:23
i had max make me a disc recently, i think it was all water cut, even the holes in it.  not sure how thick the original is, but you could get it made thinner too from stainless, 4mm is fine.  and a bit smaller, to take a smaller caliper.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 21, 2017, 06:18:44
Haven't used the Kosos myself, but only heard good things. Will probably be going with them when I get going with my build. Seems like a quality brand. I believe Acewell uses similar setup too.

Remember to set the valve clearances to .005-.006, not down to .002 as the FSM says. At least that seems to be the collective wisdom of the 1100f.net forum :) Too tight especially on the exhaust side risks burning the valves.


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Ill have to check out Acewell also, yea i too scoured over the forums and came to the same conclusion as you and left min .006 i think better to have too much than not enough may sound shit but wont fuck the valves.

Hopefully all the shims are ready would be cool to put them in fit the carbs and see if i can fire her up  (very wishful thinking) i really want to hear the Delvic pipes.

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 21, 2017, 06:19:16
Haven't used the Kosos myself, but only heard good things. Will probably be going with them when I get going with my build. Seems like a quality brand. I believe Acewell uses similar setup too.

Remember to set the valve clearances to .005-.006, not down to .002 as the FSM says. At least that seems to be the collective wisdom of the 1100f.net forum :) Too tight especially on the exhaust side risks burning the valves.


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Ill have to check out Acewell also, yea i too scoured over the forums and came to the same conclusion as you and left min .006 i think better to have too much than not enough may sound shit but wont fuck the valves.

Hopefully all the shims are ready would be cool to put them in fit the carbs and see if i can fire her up  (very wishful thinking) i really want to hear the Delvic pipes.

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 21, 2017, 06:19:45
Haven't used the Kosos myself, but only heard good things. Will probably be going with them when I get going with my build. Seems like a quality brand. I believe Acewell uses similar setup too.

Remember to set the valve clearances to .005-.006, not down to .002 as the FSM says. At least that seems to be the collective wisdom of the 1100f.net forum :) Too tight especially on the exhaust side risks burning the valves.


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Ill have to check out Acewell also, yea i too scoured over the forums and came to the same conclusion as you and left min .006 i think better to have too much than not enough may sound shit but wont fuck the valves.

Hopefully all the shims are ready would be cool to put them in fit the carbs and see if i can fire her up  (very wishful thinking) i really want to hear the Delvic pipes.

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 21, 2017, 06:21:05
i had max make me a disc recently, i think it was all water cut, even the holes in it.  not sure how thick the original is, but you could get it made thinner too from stainless, 4mm is fine.  and a bit smaller, to take a smaller caliper.
Hey brad what am i looking at to get a disc done roughly?

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Jun 21, 2017, 07:34:37
Hopefully all the shims are ready would be cool to put them in fit the carbs and see if i can fire her up  (very wishful thinking) i really want to hear the Delvic pipes.

Now that's something at least I would like to see/hear a video of :)


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: brad black on Jun 21, 2017, 08:01:04
Hey brad what am i looking at to get a disc done roughly?

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dunno.  i would have got a trade price plus i had some other stuff done and i don't recall what it ended up being.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 22, 2017, 00:19:19
I just messaged the seller for my CR carbs to see what tgey came off, as luck would have it a CB 750 and it was just jetted and tuned hopefully its pretty close to spot on once fitted

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: esmoojee on Jun 22, 2017, 03:16:12
You shouldnít have to do much with the carbs.  Mine were pre-jetted and it runs like a top.  Just needed a sync.  I read earlier that you may need a steering stabilizer.  I can attest to this, mineís pretty twitchy without it.  I have a cbr954 front end on it. I ended up buying a ohlins that came off the ninja and had it re-valved.  It cost me a total of $200 with the re-valve.  It was definitely worth it.  It looks good man.  I canít wait to see when itís finished.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 22, 2017, 04:46:36
You shouldnít have to do much with the carbs.  Mine were pre-jetted and it runs like a top.  Just needed a sync.  I read earlier that you may need a steering stabilizer.  I can attest to this, mineís pretty twitchy without it.  I have a cbr954 front end on it. I ended up buying a ohlins that came off the ninja and had it re-valved.  It cost me a total of $200 with the re-valve.  It was definitely worth it.  It looks good man.  I canít wait to see when itís finished.
Thats cool do you have photos of the dampener installed ?

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: esmoojee on Jun 22, 2017, 13:12:12
Not currently. Ill try to take some tonight. I had a tab welded to the steering stop off the steering neck and a stabilizer clamp on the fork.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 22, 2017, 18:05:16
Not currently. Ill try to take some tonight. I had a tab welded to the steering stop off the steering neck and a stabilizer clamp on the fork.
Awesome always interested to seebhow others overcome these issues, how much shorter were the forks you put on compared to stock, i think there was 4cm difference in length between stock and gsxr.

I was looking at second hand gsxr dampners can puck them up fairly cheap, then for shits and giggles typed in ohlins 😨 get what you pay for i guess, be a bit out of my budget.

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: esmoojee on Jun 22, 2017, 23:05:11
I think my shocks are the same length as yours. They should be the same as a gsxr.  I believe theyíre 27.5Ē in length.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 23, 2017, 22:57:11
Esmoojee your bike looks sweet as, The mono shock and swing arm conversion with that seat looks pimp finished professionally ill be happy if mine is half as sweet 
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: esmoojee on Jun 24, 2017, 12:49:51
Thanks man, it took me a long time.  I still keep making upgrades.  I took her out on Mulholland drive yesterday and had a blast.  However, I think Iím getting too old for clip ons.  I decided to switch to my 3Ē hi-rise clip ons over the cbrís.  I switched out my foot pegs recently as well to gsxrís over the yamahaís.  Itís a constant project but itís fun.  Iím considering swapping the front end to a yamaha r1.  I have an extra lying around.  I canít decide.  Keep up posting pics.  I like to see other cbíers bikes.  I have an affinity for them.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 25, 2017, 01:18:58
Thanks man, it took me a long time.  I still keep making upgrades.  I took her out on Mulholland drive yesterday and had a blast.  However, I think Iím getting too old for clip ons.  I decided to switch to my 3Ē hi-rise clip ons over the cbrís.  I switched out my foot pegs recently as well to gsxrís over the yamahaís.  Itís a constant project but itís fun.  Iím considering swapping the front end to a yamaha r1.  I have an extra lying around.  I canít decide.  Keep up posting pics.  I like to see other cbíers bikes.  I have an affinity for them.
With the R1 pegs did yoy weld brakets on to mount them ? Im jealous that you get to ride Mulholland ive watched heaps of clips fmof that

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: esmoojee on Jun 25, 2017, 14:35:54
No, I cut down the original peg brackets and drilled and tapped them.  No welding required.  All bolt on.  Mulholland is fun, Angeles crest hwy is just as fun too!  Itís actually closer to where I live. 
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jun 26, 2017, 05:16:18
No, I cut down the original peg brackets and drilled and tapped them.  No welding required.  All bolt on.  Mulholland is fun, Angeles crest hwy is just as fun too!  Itís actually closer to where I live.
You inspired me

(https://uploads.tapatalk-cdn.com/20170626/5bc26d87d11f1dfe7c4e8caad24473ab.jpg)
(https://uploads.tapatalk-cdn.com/20170626/b8e0842a0ff1da089e3e7d2eb866b246.jpg)

My old man is looking for an excuse to test out the new mill so ive ordered the rearsets came with master cylinder and calipers not sure if ill be able to use the caliper or not have to sus it out when i get home.

Did you end up getting a chance to take a pic of the dampner set up ? Id love to see what you did to those peg brackets also 👌no just trying to work out what dampner and bracket to get i cant remeber the diameter of the fork tube :/

I was looking at Dakota speedos but theyre a little cost prohibitive
(https://uploads.tapatalk-cdn.com/20170626/4e48c6de6e12dccf1144984d0bf2fee2.jpg)

But oh so sweet looking. Think ill have to keep scouring the net for options but.

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jul 03, 2017, 20:42:00
So while I'm stuck up the mountain at work Ive been scouring fleabay for some additional parts required and managed to find myself a Ohlins steering damper for about $200, and an aluminium front mud guard from Kickstarter.de.

Ive been watching youtube and found this cool clip https://www.youtube.com/watch?v=WWUEAMmfgVU and Im hoping to make brackets for the front mud guard in a similar fashion, although this guy is a pro so im anticipating it taking a few attempts to get it spot on.

although Ive got the steering damper I'm still not quite sure where exactly will be the best place to mount it so its most effective any people out there who have done it previously on the cb 750 dohc that have any photos it would be much appreciated.

My goal is to have all of the seat pan, tail section and frame work done with valves reshimed so I can seal engine back up this next break. then i will strip the frame down to paint it.

The engine will need a bit of loving what does everyone do to clean it down ? most of it i wil just spray silver but i will polish up the clutch basket cover and rotor cover.

the things that are stil baking my noodle is what guages to use, and what im going to do with the headlight/ nose cone option. got a few ideas but nothing in concrete yet.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Jul 04, 2017, 06:18:17
 Nice score on the dampener and fender!

No personal experience from mounting steering dampener, but seems most common to mount it off on the right hand side just under the tank. Cleanest solution is in imo in front though, and since you have a 750 and therefore no oil cooler you have the space for that. Guess you'd need to either source or fab a mount to support it?

For engine cleaning - degreaser, wire brush and elbow grease? ;)

For covers etc that come off, media blasting if you have that available? (Blasting cases seems like a bad idea)
(https://uploads.tapatalk-cdn.com/20170704/930195d076fcef3747c234ecf2cda13a.jpg)


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jul 04, 2017, 06:50:06
Nice score on the dampener and fender!

No personal experience from mounting steering dampener, but seems most common to mount it off on the right hand side just under the tank. Cleanest solution is in imo in front though, and since you have a 750 and therefore no oil cooler you have the space for that. Guess you'd need to either source or fab a mount to support it?

For engine cleaning - degreaser, wire brush and elbow grease? ;)

For covers etc that come off, media blasting if you have that available? (Blasting cases seems like a bad idea)
(https://uploads.tapatalk-cdn.com/20170704/930195d076fcef3747c234ecf2cda13a.jpg)


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Thats a crazy set up for the damper, a mean feat of engineering. I agree trying to put it up front will make it look better ill see how technical i can get.

I had a funny feeling there was no real easy way to clean the engine i guess ill have to get an assortment of wire brushes and pipe cleaners and hook in hopefully this break i can put in a few solid weeks of work.

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Jul 04, 2017, 13:55:10
I actually think that particular mount is a kit from Japan. Don't know the details or if it's available, might be worth checking?


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: esmoojee on Jul 05, 2017, 22:49:01
Sorry man, I was wrong about the weld. That was on my nighthawk. The 750 I just drilled and tapped in the steering stop.  I canít really get in there to get a good photo.  I canít remember if itís 6 or 8... Whatever the standard mount bolt was.  I locked it down with thread lock and lock nut. 
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jul 06, 2017, 16:15:19
Sorry man, I was wrong about the weld. That was on my nighthawk. The 750 I just drilled and tapped in the steering stop.  I canít really get in there to get a good photo.  I canít remember if itís 6 or 8... Whatever the standard mount bolt was.  I locked it down with thread lock and lock nut.
Now thats a cool idea because the bottom triple clam on the front left side has a mounting point for the damper i reckon. Hopefully the damper i got is not too long, as that would be a nice discreet place to mount it.

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jul 07, 2017, 07:50:15
i was looking through my build photos and cam across a photo of the triple, im wondering if the damper will fit like you said from the stopper to the preexisting mount on the lower triple.

I just hope the 63mm stroke is correct sucks not being home so i can try it out.

Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Jul 16, 2017, 03:10:41
So the front guard arrived in the post and my wife was kind enough to show me what it looks like on the bike... although its not in the correct position give me a fair idea.. im thinking painting it all black so as not to draw much attention. The fun part will be fabricating the mountin brackets

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 04, 2017, 05:00:44
So I've been home a few days and finally got to get into my shed I decided to carry on fixing the many imperfections with the seat (https://uploads.tapatalk-cdn.com/20170804/14f8798dfd49d7356c391493d42597b7.jpg)(https://uploads.tapatalk-cdn.com/20170804/3833ab30be4899791005240eadf437b1.jpg)(https://uploads.tapatalk-cdn.com/20170804/fa7857142333d4fb15e18a0f3da4e8f5.jpg)(https://uploads.tapatalk-cdn.com/20170804/928293caf4e72f7f1d2b9ef1df450534.jpg)

I marked out the place I would be cutting out to flush mount the rear LED brake and indicator strip
(https://uploads.tapatalk-cdn.com/20170804/aa32c70999d56545052ae7a7aaeb0406.jpg)
I then thought I'd play around with the Daytona digital speedo and idiot lights I'm thinking I will mill out a hole in the top triple to flush mount the idiot lights
(https://uploads.tapatalk-cdn.com/20170804/f6dd1e5f22ad4a515c2a0239f0006fad.jpg)(https://uploads.tapatalk-cdn.com/20170804/c7769760d34c78cd9615ab1daa3a22b6.jpg)(https://uploads.tapatalk-cdn.com/20170804/39b72c6330c5c6f2108727019b256917.jpg)

I then unwrapped the front guard I got from flea bay to see what it would look like I think I will paint it satin black so as not to draw attention to it(https://uploads.tapatalk-cdn.com/20170804/7be09f737dd19103692fc48f686e95af.jpg)(https://uploads.tapatalk-cdn.com/20170804/a7aa9bd244374d60ba245fc5e264effb.jpg)(https://uploads.tapatalk-cdn.com/20170804/a22746f6d1b1e7373004d6aca7b76cd7.jpg)

I'm getting a mig welder tomorrow so I'm going to see how I go fabing an electrical tray I'm anticipating it being a little ugly


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 07, 2017, 08:15:03
(https://uploads.tapatalk-cdn.com/20170807/1cf51589c77d8397d9bd1fce415d107f.jpg). So going to try and modify this triple clamp to house the idiot lights and also take out the section where the key would normally go to house the speedo so it also sits flush with the top of the triple.


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 11, 2017, 03:33:28
Ok so it was one of those days where you have to clean the shed before you can start working in it.

So I removed the engine in preparation of spraying it and the frame.

So these are all the bolts I had to remove from the frame

(https://uploads.tapatalk-cdn.com/20170811/d89e9501f27ebf17078b2a25dc1644f4.jpg) (https://uploads.tapatalk-cdn.com/20170811/ed35ef055b5d3152d74b27d37291cd24.jpg)(https://uploads.tapatalk-cdn.com/20170811/671c858eedddd069393ad4aa89e20820.jpg)
be sure to completely remove this bracket as it gets in the way if you try to remove the engine with it still in place
 (https://uploads.tapatalk-cdn.com/20170811/24181b941748142a2978e9541ce508e0.jpg)(https://uploads.tapatalk-cdn.com/20170811/a84765036ad6f4872e9cfc7f5fa319cd.jpg)
then I removed these front engine mount brackets be sure to remove both of this completely also it's a pain in the ass trying to balance an engine that is half out whilst trying to fish out the right sized ratchet.
(https://uploads.tapatalk-cdn.com/20170811/77f2c3d1ea4bd09fdce702155e88a389.jpg)
the two on the right side at the front and one just behind the clutch there once those two are out the sub frame comes out
(https://uploads.tapatalk-cdn.com/20170811/c6b6e834c3e046af6ec09b8a16ec86ef.jpg)
The next bit involved a few F bombs and a lot of manoeuvres of which I could not recall exactly even if I wanted to
(https://uploads.tapatalk-cdn.com/20170811/c8afcc0d8986e7cb4f56deaeb2c45420.jpg)

(https://uploads.tapatalk-cdn.com/20170811/dbe0891e58c95af283d78f23cf762ca9.jpg)

Now for the fun part degreasing then stripping it back to get ready for painting (https://uploads.tapatalk-cdn.com/20170811/f9a347a8d5ab85949dce4a667e314103.jpg)(https://uploads.tapatalk-cdn.com/20170811/b4f3bfc063d4f64793fd7cdde07ca710.jpg)

Now I'm out of degreaser so I'm pulling up stumps I painted up some of the parts now waiting for everything to dry (https://uploads.tapatalk-cdn.com/20170811/f5e714d429eae39a1df57ad401f0ce7f.jpg)


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: 1fasgsxr on Aug 11, 2017, 16:13:23
How have I not seen this thread ?  Looking great !!
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Aug 11, 2017, 16:33:26
Good progress! Nice work getting the engine out. Good practice for getting it back in without scratching paint :P

Painted covers look great. Did you just degrease and clean or wirebrush/sand as well?


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 11, 2017, 23:53:51
Yea degreased, paint stripper, wire brush, sandpaper then mineral turpentine and finally the wax and grease remover. Surprising how long it takes to get it back to where you want it not looking forward to all the fins on the engine.

I've doused the engine with degreaser so later this arvo I'll try to sand back the frame and paint it up (https://uploads.tapatalk-cdn.com/20170812/b0b364a1562c4272e614079c26779887.jpg)


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 12, 2017, 05:03:41
So I made a few more runs, late start today had to attend pre natal class gonna have to get this project near completion over the next week (https://uploads.tapatalk-cdn.com/20170812/546831ec6a6f6f2901a74af5f8830c0d.jpg)(https://uploads.tapatalk-cdn.com/20170812/52d4bc152f30d1cab1b0bf95097dab03.jpg)(https://uploads.tapatalk-cdn.com/20170812/036cc4b6aab93433742702fa495d66c1.jpg)(https://uploads.tapatalk-cdn.com/20170812/db721baafcf2b5639137caedd97bad02.jpg)(https://uploads.tapatalk-cdn.com/20170812/96bb5c3f0bfcf086bab589cce6e7670c.jpg)

The garage looks like a bomb just went off but I think that's still classified as progress


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 12, 2017, 06:46:45
Few more runs on the board before dinner got everything in paint stripper ready for tomorrow (https://uploads.tapatalk-cdn.com/20170812/8b7a7c5f45675dcef30d120701f8e744.jpg)(https://uploads.tapatalk-cdn.com/20170812/469c981182ec9a17791329c1571099f6.jpg)


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: Popeye SXM on Aug 12, 2017, 18:08:16
gonna have to get this project near completion over the next week

Errr  I hope you meant week(s) You are making great progress, but....... You will end up frustrated and hating the bike if you push too hard. Good luck and keep up the great work  :) I wish you both well for the big day  :-*
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 12, 2017, 19:56:42
Lol it's true, I'm fly in fly out so I have a full 84 hrs primary focus is to get frame de tabbed, stripped and painted and engine striped and repainted then back in the frame so she's rolling again anything after that is a bonus hopefully the seat will also be finished
(https://uploads.tapatalk-cdn.com/20170812/8270393fb3cd0c2fb38d538b3939a4eb.jpg)(https://uploads.tapatalk-cdn.com/20170812/282fa52ebd55b63d12c29e1c14455eeb.jpg)
Paint stripper didn't work as well as I had hoped, apparently if you wrap it in foil dull side down it's more effective so I'm off to get some more stripper then back to it

Dogs are walked and fed washing done and hung out should have a full day at it


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 13, 2017, 00:06:24
I spoke too soon apparently there is a BBQ we have to attend

(https://uploads.tapatalk-cdn.com/20170813/b61f1707244e8e99e58e5b60cc57fc5a.jpg)
First I gernied all the parts down to see what was left to get off (https://uploads.tapatalk-cdn.com/20170813/f46380a9f06f6a3509f01fbf0374cc7c.jpg)
I'm not convinced the foil made any difference
(https://uploads.tapatalk-cdn.com/20170813/f1ea673a4cbc536ea01adc6ad2971f69.jpg)
Putting rust converter on after I hit the pieces with the wire brush
(https://uploads.tapatalk-cdn.com/20170813/d48073db55c44d7b64eb9199474ed433.jpg)(https://uploads.tapatalk-cdn.com/20170813/6d5380c8b9c29bd87f3930bb4dbd6265.jpg)(https://uploads.tapatalk-cdn.com/20170813/f952813e7ec7507ec0d118de9666400e.jpg)(https://uploads.tapatalk-cdn.com/20170813/1ec2d7c4ffea362b202ffa4ccb3e325f.jpg)

Then onto the frame
(https://uploads.tapatalk-cdn.com/20170813/8e4b3139ae2eb55e802311c22a09f8d4.jpg)

Thais is as far as I got (https://uploads.tapatalk-cdn.com/20170813/ecc02c9936d9160690c0ac335594e163.jpg)(https://uploads.tapatalk-cdn.com/20170813/01bdc2f3fcc2a3498ec27a3ed9e09858.jpg)




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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 13, 2017, 04:39:12
Keep in mind, a little shit left on there is gonna come off when scuffed up for the paint job anyhow. What are you painting with?
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 13, 2017, 04:54:55
Yea I'll have to give it a scuff to smooth it out after the rust converter

(https://uploads.tapatalk-cdn.com/20170813/92862aa2ca4f22c27ff958a6870abe84.jpg)

Unfortunately spraying isn't going to be too tech so I thought I'd use this

(https://uploads.tapatalk-cdn.com/20170813/f0a2529a46072fa1ba732d1ee586fa67.jpg)(https://uploads.tapatalk-cdn.com/20170813/b981e9e0c2b0b48cacf8eea4ffe956b2.jpg)(https://uploads.tapatalk-cdn.com/20170813/d26e17af34d34e73a9e47d24be32c368.jpg)

This is the evolution of the frame batteries for the drill are both flat waiting for it to charge so I can finish the job and get the rust converter onto it


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 13, 2017, 05:47:25
(https://uploads.tapatalk-cdn.com/20170813/f6766277b8a345e9d4873ea91c337005.jpg)(https://uploads.tapatalk-cdn.com/20170813/b89cf422da727f18cc7041ee4d77e9b4.jpg)

That's where I finished up at everything in rust converter tomorrow I'll rough it up and spray then get onto the engine


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 13, 2017, 07:22:01
Fwiw I keep hearing good things about appliance epoxy for frames.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 13, 2017, 07:46:48
yea i figured if its good for roll cages it should be fairly durable. That said im still paranoid of scratching the frame when i  reinstall the engine.

Im thinking about bubble wrapping the frame when i go to in to install the engine, not sure how far ill get tomorrow as Im heading across town to my dads to have a crack at modifying the triple clamp on the mill to house the speedo and idiot lights.

If we get enough time we will try to make up some adapter plates so that the R6 rearsets can mount im thinking of using the original bolts that held the old rearsets then tap in some threads.

I  made up a wooden template for us to get the holes right

 
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 13, 2017, 07:47:40
(https://uploads.tapatalk-cdn.com/20170813/7a3888c86277e6af12770635b9809182.jpg)

It's pretty ugly


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 13, 2017, 08:43:07
No bunble wrap, use the thin foam inderlay for floating floors. Its strong and thin works awesome. Cheap too.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 14, 2017, 06:58:23
Ok so today made some good progress managed to hit the frame again with the wire brush then paint it up.

First I had to de tab the frame
(https://uploads.tapatalk-cdn.com/20170814/34e75b6b39387fa4ef59ffe32c19c468.jpg)(https://uploads.tapatalk-cdn.com/20170814/e806d4962da59e8c5965ff316d33dee9.jpg)(https://uploads.tapatalk-cdn.com/20170814/e61758a77ed7ff0d50c488a8ca8284a3.jpg)(https://uploads.tapatalk-cdn.com/20170814/9377e1aaabb73be6806dce3e94f52bd0.jpg) tabs done

Then on to spraying. Let me go on the record as saying I'm not even a spray painters, butchers, second cousins, Guinea pigs vet.

(https://uploads.tapatalk-cdn.com/20170814/87b6872a51d1b18a052ae1f6641d26f6.jpg)(https://uploads.tapatalk-cdn.com/20170814/d2ad22c57eb39cc507dcbaf895c17ab9.jpg)(https://uploads.tapatalk-cdn.com/20170814/48eaa76cbf23d34ae1812aa0d02e37c0.jpg)(https://uploads.tapatalk-cdn.com/20170814/5cc8e2fdc15b6a5f5d129e0a396d5066.jpg)(https://uploads.tapatalk-cdn.com/20170814/73a2456f7f1942ff5f26a9a36598f3e5.jpg)(https://uploads.tapatalk-cdn.com/20170814/9c4e9f53d99de7ae2e06713ea75e577b.jpg)

Luckily the clothes line is weight rated 🤙

Next we went to the mill to modify the top triple

(https://uploads.tapatalk-cdn.com/20170814/16b08c3ed6fe6e7efede3cc1e2d48ce0.jpg)

Set up is everything (https://uploads.tapatalk-cdn.com/20170814/d8be614413ccef89886958a168743d33.jpg)

First we wanted to make the slot to house the idiot lights
(https://uploads.tapatalk-cdn.com/20170814/6ca7f765efbecc275abbb4b338607eb3.jpg)
(https://uploads.tapatalk-cdn.com/20170814/506bd73ca2d5ee325f10bf99f6bc7c5a.jpg)

Originally there was a Suzuki emblem countersunk into the triple and its dimensions were larger top to bottom than the idiot lights so we chamfered all around the gauge.

Next we decided to use the hole that use to mount the ignition, and bore it out large enough to house the speedometer.

We had to be careful not to take out any of the ribs on the underside of the triple
(https://uploads.tapatalk-cdn.com/20170814/ad6cf3cf26b1596c718db8679b1321a5.jpg)(https://uploads.tapatalk-cdn.com/20170814/7cd496513d525669bd7fe3573a2a7434.jpg) it was slow going so we tried our luck with a 54mm circular cutter (https://uploads.tapatalk-cdn.com/20170814/8d846e9b4a0a3e8346ae868b9a04d794.jpg)

It paid off

(https://uploads.tapatalk-cdn.com/20170814/0e9d592d74e8633d21aad8c5e66e714e.jpg)

Then it was back to boring until we got it to the required size

(https://uploads.tapatalk-cdn.com/20170814/b8dbd038a821e83c17471090630eb9b5.jpg)

Then the final test to see if it's the right size
(https://uploads.tapatalk-cdn.com/20170814/2aea56004f38bc7c26d8c887aa96be10.jpg)

Success!!  We then needed to drill holes and tap threads on the underside of the triple to secure the gauges
(https://uploads.tapatalk-cdn.com/20170814/260e06c4b27f9037acfadb5f6c55395e.jpg)

(https://uploads.tapatalk-cdn.com/20170814/2a77b462fdfca1276bebf1ec2c0706e7.jpg)(https://uploads.tapatalk-cdn.com/20170814/a2f36a0cecd9ae7ae9a84ccb33ac2099.jpg)

Pretty happy with today's progress, tomorrow I'll get some more paint and put another few coats on the frame and the discretely bring it in to the lounge room and put it under the heating ducts to try and bake it... then it's on to the engine




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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: dakine_surf on Aug 14, 2017, 08:20:03
Wow looks sweet, I really dig it, awesome machining


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 14, 2017, 08:23:41
Can't take credit for the machine work that was the old man he's the one with all the cool toys


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Aug 14, 2017, 08:28:46
Top triple came out great, fits really well with the speedo. That's a good looking unit btw. Nice work!


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 14, 2017, 08:32:33
It's from Daytona I can't wait to see them both lit up.... although that's going to be a little way down the track yet


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: CrabsAndCylinders on Aug 14, 2017, 16:12:30
Yeah, nice work on the triple clamp!
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 15, 2017, 04:52:05
Ok so I drilled and taped a thread in the rear of the Triple to hold the speedo
(https://uploads.tapatalk-cdn.com/20170815/fa7033323aefdda5aa8f98bca8e990b4.jpg)

(https://uploads.tapatalk-cdn.com/20170815/97b2aba52f770f31663404122e2bebd2.jpg)

I messed up the M5 tap attempt and had to re drill it and go up to a M6

(https://uploads.tapatalk-cdn.com/20170815/e9bc5b21a8a45fbf09ff2fed44750afc.jpg)

Thankfully I nailed it second time round, I then decided to see how hi temp caliper paint would come up I figured if I didn't like it I would just strip it and get it anodised

(https://uploads.tapatalk-cdn.com/20170815/d8ee6220eeb8d305f70b3d2ba3460af1.jpg)
(https://uploads.tapatalk-cdn.com/20170815/f6b5eed17019d7f41a906dcb5ad50661.jpg)
(https://uploads.tapatalk-cdn.com/20170815/eddf1f63430d25fbf8bfc54d7f90966b.jpg)

I'm pretty happy with the way it looks see how it lasts

I then touched up a few parts on the frame I wasn't happy with and managed to sneak it into the lounge room without too much protest from the minister for war and finance

(https://uploads.tapatalk-cdn.com/20170815/064bc6bcb3d401c74f6410d88005ee42.jpg)

Was hoping to achieve more but such is life. Tomorrow engine I'll have to work out how the hell im going to prop it to spray. I'm thinking this one may be a little too much for the clothesline

Open to suggestions I purchased some steel rod and was thinking maybe using wood either that or I'll attempt my first mig welding project





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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 16, 2017, 04:41:32
So when I went to the auto shop to get some heave duty degreaser I noticed a atv jack on sale for $70

(https://uploads.tapatalk-cdn.com/20170816/c46dad484451121bca8becf7ac8a6efe.jpg)

(https://uploads.tapatalk-cdn.com/20170816/6fadfcbac3a8cac835dc51dedfc51a9f.jpg)

Probably couldn't raise a family underneath it but it will do while the degreaser was soaking in I thought I'd try my hand at rebuilding the rear brake caliper

(https://uploads.tapatalk-cdn.com/20170816/eb0d9bec473eb5b9a180f6ee48040570.jpg)

So being a noob and a bit of a retard I remover the brake line DONT do this as I learned you'll need that connected to pump the caliper pistons out later .

(https://uploads.tapatalk-cdn.com/20170816/d7ff26a86a83a82aa977f22727a36775.jpg)

So you have to remove this retaining plate to allow you to slip out the two pins that hold in the brake pad

(https://uploads.tapatalk-cdn.com/20170816/7f32f074ae4641e9d550e9e9096c2257.jpg)

I then pushed both pads together so as not to jag on the pins as I pulled them
Out
(https://uploads.tapatalk-cdn.com/20170816/12a4c3acc368acf06305ae6d1e2b7cb3.jpg)
(https://uploads.tapatalk-cdn.com/20170816/aaceb283ff57b45f0dc61cec375465b6.jpg)(https://uploads.tapatalk-cdn.com/20170816/1e244cd3b65fc6e885ad5160102ad82c.jpg)

It was at this point the light bulb went on and I reconnected the brake lines and began to pump the pedal

(https://uploads.tapatalk-cdn.com/20170816/2bf3960e8b8f63265e6decfc405a7a61.jpg)

Unfortunately one of the pistons was slightly seized and being a dumbass I didn't put something in place to stop one coming out while the other one came along.
(https://uploads.tapatalk-cdn.com/20170816/5ff871e5dea77d305a1aefbbcf745293.jpg)

Take two

(https://uploads.tapatalk-cdn.com/20170816/904b16a04f2cb5e1680b4244e74f6cd2.jpg)(https://uploads.tapatalk-cdn.com/20170816/d4c3eab946a43894370bbe664ab249c3.jpg)

Finally out but upon closer inspection I wasn't happy with the state of them so I've ordered some more unfortunately this means this job won't be getting completed this break boo

I've soaked  the caliper in thinners to eat away the paint and hopefully tomorrow I'll strip it back and spray it up



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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 17, 2017, 04:22:42
So I found a few runs on the triple so had to fix it up, or risk having it do my head in every time I ride it.

Then I turned my attention to the caliper that I had left soaking over night

(https://uploads.tapatalk-cdn.com/20170817/75c093c203561ed0941dee72cde8cbb4.jpg)(https://uploads.tapatalk-cdn.com/20170817/8682615a6aca19c28659681c4d55fc73.jpg)
(https://uploads.tapatalk-cdn.com/20170817/3126b2ce7a5be4a1f2df460d68ab7377.jpg)

After a whole lot of scrubbing with various brushes it ended up coming up not too bad
(https://uploads.tapatalk-cdn.com/20170817/0f96efbb4385b7bf864dc617adb3380b.jpg)(https://uploads.tapatalk-cdn.com/20170817/5ed264e64f6f305995bf67c9b5cf7128.jpg)(https://uploads.tapatalk-cdn.com/20170817/4df19067147285c55469bf59312ba1ba.jpg)(https://uploads.tapatalk-cdn.com/20170817/ff6173e7c568e0988adb3b0d24ad60c2.jpg)(https://uploads.tapatalk-cdn.com/20170817/6be2485f08ee63e07ff6ba7844a9ac84.jpg)

Once it was ready I reinserted the pistons, valve and some bolts to stop the paint getting in and undoing all my hard work
(https://uploads.tapatalk-cdn.com/20170817/016d546e192dbd747e2aaa18f563b5ff.jpg)(https://uploads.tapatalk-cdn.com/20170817/65febc0ac1e9f4335b89d0ae5c043408.jpg)

I then set up a bracket to hole the caliper so I could paint it (https://uploads.tapatalk-cdn.com/20170817/77980a85a255bc509a808c1ecd7811a7.jpg)

(https://uploads.tapatalk-cdn.com/20170817/3b24ea1ab68387165429b30228b6b2db.jpg)
(https://uploads.tapatalk-cdn.com/20170817/c3d656cdafae5e91a4430402ad1c7636.jpg)(https://uploads.tapatalk-cdn.com/20170817/32f701c0a5df5823fd89aa57885decc4.jpg)(https://uploads.tapatalk-cdn.com/20170817/b60d54d3a4c80af7a7c00faa06182779.jpg)

Tomorrow after the paint has hardened I'll try to grind back the paint off the Honda see how it goes


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 17, 2017, 05:15:45
Sitting in the lounge room admiring my crazy can spray job I realised I needed to replace the grease nipple on the swing arm

Unfortunately it was snapped off in the hole
(https://uploads.tapatalk-cdn.com/20170817/471559ffe0dc0e0f573934f5145017bd.jpg)

Got the easy out

(https://uploads.tapatalk-cdn.com/20170817/f3119ce6caa9642e750d865d49d6028f.jpg)

Then boom just like new (https://uploads.tapatalk-cdn.com/20170817/20c49c9e308227831ae23b535882e081.jpg)


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 17, 2017, 05:24:43
Sitting in the lounge room admiring my crazy can spray job I realised I needed to replace the grease nipple on the swing arm

Unfortunately it was snapped off in the hole
(https://uploads.tapatalk-cdn.com/20170817/471559ffe0dc0e0f573934f5145017bd.jpg)

Got the easy out

(https://uploads.tapatalk-cdn.com/20170817/f3119ce6caa9642e750d865d49d6028f.jpg)

Then boom just like new (https://uploads.tapatalk-cdn.com/20170817/20c49c9e308227831ae23b535882e081.jpg)


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 18, 2017, 05:23:36
Ok so I sprayed up the engine, it's good from a far but far from good

(https://uploads.tapatalk-cdn.com/20170818/bf5ea618a7fe68675a348b36c387dec6.jpg)(https://uploads.tapatalk-cdn.com/20170818/592ed63faef74902d23623cc8bd957d6.jpg)(https://uploads.tapatalk-cdn.com/20170818/cadc25da7504e151f952c5b6a442075d.jpg)(https://uploads.tapatalk-cdn.com/20170818/e2e31550a73aa325d73bde73113017d5.jpg)(https://uploads.tapatalk-cdn.com/20170818/5f1e9acb8a3a7bcbb5c8f91d19c53be1.jpg)

See how I go, I will have to let it dry for at least another day and maybe try to install it on Sunday

I've decided I'm not happy with the way the triple came up in paint so I going to send it away to get anodised, hopefully that will get done while I'm away at work.

Tomorrow I'll try to touch up the brake caliper so you can see the Honda logo, not sure how much more I'll achieve this break.

Still have to send the rear disc away to get cross drilled

Fabricate the rear set brackets and get on to the seat section lol the list goes on maybe I'll try my hand at the seat again


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 19, 2017, 20:06:15
Ok so I'll probably need to polish up the side covers more but I fly out to work tomorrow so wanted to put everything back together so bolts and stuff don't disappear

Yesterday I sprayed over the Honda logos with black paint then tried to polish it back to bring it up somewhat newer
(https://uploads.tapatalk-cdn.com/20170819/23e96673f6fadbc7d583f526e9773844.jpg)(https://uploads.tapatalk-cdn.com/20170819/f9e3d267f64b632398251f03f9c5e1f5.jpg)(https://uploads.tapatalk-cdn.com/20170819/ccf63f573facb55ea107221de7877c29.jpg)

This is how the brake caliper came up (https://uploads.tapatalk-cdn.com/20170819/044f28bf73958f5d317f079c972da038.jpg)

I was going to try and remake a seat but the paint on the frame has only cured for a few days and it's been cold so I'm worrried I'll scratch it ir I try to put it back together





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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 20, 2017, 06:30:09
Well this is it

(https://uploads.tapatalk-cdn.com/20170820/c22539c2a6deee6dcf2bf8a7b8c7545e.jpg)

Fly out to work tomorrow morning just enough time to clean up the shed and put everything in a safe place

I sprayed another coat onto the frame this way it will have 6 weeks to cure

I think once I reassemble the frame and engine I may try to make a different seat pan not sure if I'm 100% happy with the original shape few too many faults

Then I need to work out where to put the electrics

Oh well it's only online shopping from here until I return can anyone recommend somewhere to get different kinds of led or projector headlights that's one of the last couple of things I need to buy


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: Popeye SXM on Aug 21, 2017, 09:15:05
Great work. Next, the fun part of turning all the shiny parts back into a motorcycle. 
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 21, 2017, 13:55:38
Yep there's the tricky bit, also doing all that without scratching anything.

The thing i think that will be most difficult thing will be the electrical


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: BigNickel on Aug 22, 2017, 07:45:23
Painting has turned out very nice. I'm looking forward to this coming back together!
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: ChopperCharles on Aug 22, 2017, 11:57:45
Why are you mounting a steering damper on this bike? With the OEM head angle and the modern forks, you're going to have miles and miles of trail. You won't need the damper at all.

Charles.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 22, 2017, 16:25:17
The forks are infact shorter, im not sure by how much maybe an inch or so plus the front tyre is smaller in diameter by 2 in. I thought that would decrease the trail ??

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: ChopperCharles on Aug 22, 2017, 18:18:15
Yes, shortening the front suspension will decrease the trail, but you've decreased the stem-to-fork offset quite a bit. The old forks had a big offset from the steering stem to the fork tubes. The new forks you have, they're almost in the same plane. That increases trail by a very large amount. Lowering the bike in the front will decrease trail by a smaller amount. You *may* be able to compensate for the offset by lowering the front of the bike, and you might even get close to stock trail numbers (for the original frame) that way. But it's highly unlikely you'll be able to get anywhere near a trail number low enough to require a steering damper. You'll have to take measurements and do the calculations, but in all likelihood, the steering damper will prove to be unnecessary, and you'll save some weight by leaving it off.

Charles.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: ChopperCharles on Aug 22, 2017, 18:36:21
Here you can see how offset effects trail. Excuse the poorly edited drawings, but you get the gist.


Charles.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 23, 2017, 00:32:07
Yes, shortening the front suspension will decrease the trail, but you've decreased the stem-to-fork offset quite a bit. The old forks had a big offset from the steering stem to the fork tubes. The new forks you have, they're almost in the same plane. That increases trail by a very large amount. Lowering the bike in the front will decrease trail by a smaller amount. You *may* be able to compensate for the offset by lowering the front of the bike, and you might even get close to stock trail numbers (for the original frame) that way. But it's highly unlikely you'll be able to get anywhere near a trail number low enough to require a steering damper. You'll have to take measurements and do the calculations, but in all likelihood, the steering damper will prove to be unnecessary, and you'll save some weight by leaving it off.

Charles.
Wont be able to lower it anymore unfortunately she sits very low im actually worried it may be a little too low, wont know till i ride it.

I'll have to sit downnand work it out when im back home from work in 6 weeks.

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 23, 2017, 05:16:20
Wont be able to lower it anymore unfortunately she sits very low im actually worried it may be a little too low, wont know till i ride it.

I'll have to sit downnand work it out when im back home from work in 6 weeks.

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Did you measure? 4-4.5 inches ground clearance is the lowest you can really go. And with that, don't hit any big bumps lol.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: ChopperCharles on Aug 23, 2017, 10:33:21
FYI, I went with 93-95 GSXR front triples for this reason. They have more offset than later trees, and they work with Hayabusa forks. (I used the 94 GSXR forks though, because that allowed me to run a mechanical speedometer and OEM gauges). A little more trail is not a big deal, it makes the bike stable. I'm just saying that the steering damper is likely completely unnecessary.

Charles.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 23, 2017, 16:25:06
Did you measure? 4-4.5 inches ground clearance is the lowest you can really go. And with that, don't hit any big bumps lol.
Its going to be very close to that amd agreed no bumps

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 23, 2017, 16:28:54
FYI, I went with 93-95 GSXR front triples for this reason. They have more offset than later trees, and they work with Hayabusa forks. (I used the 94 GSXR forks though, because that allowed me to run a mechanical speedometer and OEM gauges). A little more trail is not a big deal, it makes the bike stable. I'm just saying that the steering damper is likely completely unnecessary.

Charles.
Yea these are 2008 gsxr 750 forks, they are definitely shorter but im unsure the difference in offset.
Once i get home i will have to look im not too sure what the stock rake and trail is on the DOHC is. The powers been out all night on site and is still off so i was conserving my battery so the alarm would go off.
Hopefully there is power in the office then ill be able to do a bit of R&D, i think cognito moto had a thing on it saying that tue change wasnt to drastic with this conversion but we'll see.

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 24, 2017, 08:32:36
Has anyone reading this done the Gsxr fork conversion on their cb 750 dohc and simply pressed a new stem in ? Im interested to see how it handles with a 17" rim on it

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 24, 2017, 09:21:07
Has anyone reading this done the Gsxr fork conversion on their cb 750 dohc and simply pressed a new stem in ? Im interested to see how it handles with a 17" rim on it

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Hold on, can you give me this info:

Wheel size front and rear
rear shock length
what swingarm
Length difference of front end
tire sizes being used

Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 24, 2017, 16:43:00
110/70 front 150/ 60 rear both on 17" rim, swingarm original cb 750 f2 720mm fork length the original were 780mm with 19" rim but i cant remember tyre size

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 24, 2017, 17:05:39
110/70 front 150/ 60 rear both on 17" rim, swingarm original cb 750 f2 720mm fork length the original were 780mm with 19" rim but i cant remember tyre size

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Rear shock length?
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 24, 2017, 19:15:18
Im going to have to ask the wife to measure it up sorry im overseas atm ... leave it with me im trying to work out how to explain clevis to clevis :/

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 24, 2017, 19:33:23
Im going to have to ask the wife to measure it up sorry im overseas atm ... leave it with me im trying to work out how to explain clevis to clevis :/

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Lol!!! Ur drop in the front is right at 3ish inches, bit i need the shcok lengtg to figure in any rear drop. If its the same, 3 inches is actually sizable and will have a big effect up front.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 25, 2017, 04:42:04
(https://uploads.tapatalk-cdn.com/20170825/4ae917dad2db6ffb80b33fd2c214505a.jpg)

35cm is the call

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 25, 2017, 06:48:11
Ok with the tires and everything you're .5 lower in the rear, and 4 lower up front. That's before factoring ib the rear shock, which I think is longer that stock. Stock I think was around 13. If that's true, basically the front end of the bike is 4 inches lower, and the rear is stock. That's a big difference homie. I'm not sure how rideable that will be.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: Cookie on Aug 25, 2017, 06:54:31
...Stock I think was around 13.

Stock length in the F is 14". Either way, you're right: that's a pretty extreme alteration
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 25, 2017, 06:56:19
Stock length in the F is 14". Either way, you're right: that's a pretty extreme alteration

Ok. .5 rear drop, 4.0 front drop. So 3.5 front drop normalized. That still may not be rideable.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 25, 2017, 08:06:35
So how could this be countered?  Getting triples to lower the forks ?

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Aug 25, 2017, 08:38:48
When you say not rideable, do you mean because the forward lean decreases rake angle and thereby trail? To some extent that would be countered by the smaller offset, right?

What is the offset in the GSXR triples? I believe stock is 45mm?


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 25, 2017, 08:39:37
So how could this be countered?  Getting triples to lower the forks ?

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Assemble the bike and measure the rake. If it's poo poo that's one way yes. I've only seen that done for 1 inch though, you'd likely want to do at least 2 inches.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 25, 2017, 08:41:09
When you say not rideable, do you mean because the forward lean decreases rake angle and thereby trail? To some extent that would be countered by the smaller offset, right?

What is the offset in the GSXR triples? I believe stock is 45mm?


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Yes and no. The rake is going to be shit most likely. No offset on the world is going to fix that. It will be extremely quick.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Aug 25, 2017, 09:01:25
My knowledge about this is mostly theoretical, but from what I understand rake angle in itself doesn't affect handling that much? What affects handling is primarily the trail number (which is of course a product of rake angle). In the "Tony Foale test" (https://tonyfoale.com/Articles/RakeEx/RakeEx.htm) they experimented with even using even 0 degree rake angle and found it handled pretty normally as long as the trail was kept the same.

..just saying that if the decreased rake angle results in less trail (and thereby twitchy/dangerous handling), then a smaller offset in the triple would pull the trail in the opposite direction. Could be like jag767 says it's way too small difference to compensate for the result of the decreased angle though.

Measuring rake angle with the current setup sounds like it'd be a good idea to put numbers on the change? (good luck getting the wife to do that  ;) )

Does the forward lean have other implications than rake/trail? Would weight distribution change and affect handling?
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 25, 2017, 09:04:31
My knowledge about this is mostly theoretical, but from what I understand rake angle in itself doesn't affect handling that much? What affects handling is primarily the trail number (which is of course a product of rake angle). In the "Tony Foale test" (https://tonyfoale.com/Articles/RakeEx/RakeEx.htm) they experimented with even using even 0 degree rake angle and found it handled pretty normally as long as the trail was kept the same.

..just saying that if the decreased rake angle results in less trail (and thereby twitchy/dangerous handling), then a smaller offset in the triple would pull the trail in the opposite direction. Could be like jag767 says it's way too small difference to compensate for the result of the decreased angle though.

Measuring rake angle with the current setup sounds like it'd be a good idea to put numbers on the change? (good luck getting the wife to do that  ;) )

Does the forward lean have other implications than rake/trail? Would weight distribution change and affect handling?

He is using the 17 up front, the offset is fine for that wheel. He can add rake to the triple, but that will only make the bike lower, which is already an issue
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Aug 25, 2017, 09:16:09
Not sure I understand what the triple tree offset has to do with wheel size?

Rake angle, offset, fork length and wheel size all affect trail of course, but given a 17" wheel, different offset would give different trail.

Not suggesting he goes chopper with raked triples :)


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 25, 2017, 09:58:26
Not sure I understand what the triple tree offset has to do with wheel size?

Rake angle, offset, fork length and wheel size all affect trail of course, but given a 17" wheel, different offset would give different trail.

Not suggesting he goes chopper with raked triples :)


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Maybe im wrng but isnt the offset of the triple match to thr wheel size?  Honestly, a few degrees of rakr on a triple with more offset and a drop could fix the issue, potentially. Id actually have to figure out the numbers. Getting someone to design and cnc it wil be expensive.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 25, 2017, 16:00:10
Ok so Devin the legend from conito moto sent me this
(https://uploads.tapatalk-cdn.com/20170825/4330fa182f9436ead788749a6cfc4b36.jpg)

Those numbers arent too far from stock trail but i still need to work out rake, and like you said Lights out first my pregnant wife would have to install the motor rebuild the frame put the wheels on and then somehow understand how to work out the rake ....chances are slim

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 25, 2017, 16:34:52
My knowledge about this is mostly theoretical, but from what I understand rake angle in itself doesn't affect handling that much? What affects handling is primarily the trail number (which is of course a product of rake angle). In the "Tony Foale test" (https://tonyfoale.com/Articles/RakeEx/RakeEx.htm) they experimented with even using even 0 degree rake angle and found it handled pretty normally as long as the trail was kept the same.

..just saying that if the decreased rake angle results in less trail (and thereby twitchy/dangerous handling), then a smaller offset in the triple would pull the trail in the opposite direction. Could be like jag767 says it's way too small difference to compensate for the result of the decreased angle though.

Measuring rake angle with the current setup sounds like it'd be a good idea to put numbers on the change? (good luck getting the wife to do that  ;) )

Does the forward lean have other implications than rake/trail? Would weight distribution change and affect handling?
Very interesting read

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 25, 2017, 16:59:03
If i read that right (hard to read on my phone) youve gone from 27 to 23? Thats a low number. Lots of different stress on the frame it wasnt designed for. If a custom triple is on the table, im thinking do a 1 inch drop, increase the offset, and add 2 degrees of rake in the triple. At that point I'd  wager youd be ok. The rake in the triple is a chopper thing, but i see not reason just adding a tad would hurt. If someone knows better please correct me.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 25, 2017, 21:19:27
Devin at cognito moto said that this particular set up would improve the handling although i was unable to provide him with tye rake so he was only going of the information i could provide

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 25, 2017, 21:37:06
Devin at cognito moto said that this particular set up would improve the handling although i was unable to provide him with tye rake so he was only going of the information i could provide

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I just reread. And yea, you don't need more offset with a 17. The rake is an issue though. And the ground clearance would be a potential worry for me. Can you drop the rear an inch without the rear tire hitting the seat?
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 25, 2017, 21:44:54
I just reread. And yea, you don't need more offset with a 17. The rake is an issue though. And the ground clearance would be a potential worry for me. Can you drop the rear an inch without the rear tire hitting the seat?
(https://uploads.tapatalk-cdn.com/20170826/10ca6336a8086025704d965dd7e60d66.jpg)

I don't think the tyre will hit the seat



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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 25, 2017, 22:17:12
I was asking if you could go with shorter shocks, which you definitely cant. Basically at this point in the game your only option is a custom triple.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 25, 2017, 22:59:58
I was asking if you could go with shorter shocks, which you definitely cant. Basically at this point in the game your only option is a custom triple.
Definitely cant i think the rear is at its limit plus i dont want to lower it anymore for fear of clearance issues :/ hmmm

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: CrabsAndCylinders on Aug 25, 2017, 23:16:57
I don't remember what rear wheel size you have on but can you go to a smaller rear wheel?
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 25, 2017, 23:56:45
I don't remember what rear wheel size you have on but can you go to a smaller rear wheel?
Its 17 " also

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: CrabsAndCylinders on Aug 25, 2017, 23:59:24
Aw, crap, so much for that idea.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: Popeye SXM on Aug 26, 2017, 01:22:41
If you are worried about ground clearance and rake, Cognito moto make a nice stepped top triple clamp, a cheap way of raising the front end. I suggest you put the bike back together then worry about the problems as they arise. ie if the bike has ground clearance issues raise the front or rear, IF the front end is nervous then fit a steering damper. Unless you fit a progressive damper or linkage it will make slow speed (traffic) maneuvering heavy. Most road bike owners with steering dampers are just trying to show off, how aggressive do you ride on the road?. I say go with what you have, looking great by the way, and later work out the problems or issues YOU do not like. Often I find things I expect to be a problem are not and others I had no idea cause me much swearing!!! Good luck
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 26, 2017, 01:42:25
If you are worried about ground clearance and rake, Cognito moto make a nice stepped top triple clamp, a cheap way of raising the front end. I suggest you put the bike back together then worry about the problems as they arise. ie if the bike has ground clearance issues raise the front or rear, IF the front end is nervous then fit a steering damper. Unless you fit a progressive damper or linkage it will make slow speed (traffic) maneuvering heavy. Most road bike owners with steering dampers are just trying to show off, how aggressive do you ride on the road?. I say go with what you have, looking great by the way, and later work out the problems or issues YOU do not like. Often I find things I expect to be a problem are not and others I had no idea cause me much swearing!!! Good luck
Cheers for that i think that may be the best course of action. Trial and error until complete

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Aug 26, 2017, 03:33:26
Agree with Popeye, try it out! I'd probably also measure rake, trail, ground clearance and swingarm droop just to put measured numbers on those things rather than calculated ones.

Did some calculations with the numbers available and didn't see a dramatic change in trail. Could of course be way off, but my bet is that when you get to ride it, it'll feel and handle well!


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 26, 2017, 04:59:46
Trail isn't  the problem. His nemesis will be speed bumps, and being stable at 55mph  ;D

Don't feel bad, I screwed up a bike so bad I had to cnc a new oil pan, and fab a new exhaust just to have sufficient ground clearance to clear ant hills. It happens lol.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 26, 2017, 06:31:50
Trail isn't  the problem. His nemesis will be speed bumps, and being stable at 55mph  ;D

Don't feel bad, I screwed up a bike so bad I had to cnc a new oil pan, and fab a new exhaust just to have sufficient ground clearance to clear ant hills. It happens lol.
Yea thats why i need to come up with some way to effectively mount the steering damper... and then spend the rest of my days watching out for speed bumps

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 26, 2017, 06:44:25
Yea thats why i need to come up with some way to effectively mount the steering damper... and then spend the rest of my days watching out for speed bumps

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Even with a damper 23į is worrysome, that's less than modern sportbikes. Then there's the issue of the added stress to the frame with the new head tube angle.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 26, 2017, 07:16:31
Even with a damper 23į is worrysome, that's less than modern sportbikes. Then there's the issue of the added stress to the frame with the new head tube angle.
Devin seemed to give me the impression that there was no issue and that it would improve handling..

has anyone following this thread actually done this conversion? ? I know guys who are in the process of doing this but noone has finished and tested it.

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 26, 2017, 08:25:55
Devin seemed to give me the impression that there was no issue and that it would improve handling..

has anyone following this thread actually done this conversion? ? I know guys who are in the process of doing this but noone has finished and tested it.

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At low speed, yes. But the faster you go the more twitchy itll be.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: clem on Aug 26, 2017, 19:45:46
I haven't messed with this particular swap but I have taken a modern front end and put it on an old motorcycle. Honestly the bike probably handled better before. Now it did well around town but if you really wanted to ride the bike the handling sucked. The bike didn't want to turn, would want to stand up in mid turn, etc. I wound up finding a front end that was a close match with the original equipment and the bike improved. To me, it's not worth going through all this trouble and end up with a bike that may handle worse than it did before.

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Aug 26, 2017, 19:54:36
I haven't messed with this particular swap but I have taken a modern front end and put it on an old motorcycle. Honestly the bike probably handled better before. Now it did well around town but if you really wanted to ride the bike the handling sucked. The bike didn't want to turn, would want to stand up in mid turn, etc. I wound up finding a front end that was a close match with the original equipment and the bike improved. To me, it's not worth going through all this trouble and end up with a bike that may handle worse than it did before.

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With his numbers i'd wager it'd dive into a turn more than anything, but your point is still the same.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 27, 2017, 04:42:15
I guess the proof will be in the pudding, im too far in now to turn back. I've committed to the frobt end conversion and will now have to see it through to fruition. I wish i wasnt away for another 5 weeks i could probably have it just about finished if i had that long to work on it... although that estimation may blow out as i am thinking of redoing the seat pan

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: esmoojee on Aug 27, 2017, 14:59:17
If you go with the stepped triple you should be fine. As well as a steering damper. There are lots of guys who use 17Ē rims front and back, just go to the cb1100f.net site and youíll see tonís of examples. One of the guys sells kits for the conversion to 17Ē cbr rims. I believe Freddie Spencer had 17Ē wheels on his bike. Granted he did use stock length forks. Iím not sure of the numbers on the stock forks but I donít think itíd be more than 2Ē difference. He definitely had a damper. Also, though I did change the rear suspension on my f, the bike handles very well with the damper. My trail was 4.4Ē right there with modern sports bikes.  If youíre worried about clearance you can switch to a 4-2-1 header and gives you a little more space. 
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: clem on Aug 27, 2017, 16:17:57
4.4" would be closer to a Honda shadow than any modern sport bike. They are around 3.8" and below.

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: esmoojee on Aug 28, 2017, 03:00:16
Youíre right, I went back and checked my numbers.  My trail is right about 4.  I was thinking of my nighthawk.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 30, 2017, 08:20:26
Ok so some more progress, before I left I had identified that the part of the CR carbs that inserts into the boots was the incorrect external diameter.
(https://uploads.tapatalk-cdn.com/20170830/c4369dd64e9e8c3eb81a533fff0157c5.png)
(https://uploads.tapatalk-cdn.com/20170830/1458a0c5eed1ff1090d3abe110c15197.png)

Perhaps they were set up for a SOHC I'm not sure as the seller said they were of a cb 750... Maybe he was just talking theories to sell it.
(https://uploads.tapatalk-cdn.com/20170830/cad72930f60d443aee00500567fd530c.png)

I realised that the part in question simply unscrewed

Anyway before I left for work I passed my original carbs and new CRs to my dad, I explained the predicament and asked if he could turn me up some adapters on the lathe to match the external diameter so I could use normal CV boots

(https://uploads.tapatalk-cdn.com/20170830/4212599c8f20209fc9bd83897f9af890.jpg)

This was his plan

(https://uploads.tapatalk-cdn.com/20170830/c3bc4d97fab863f07053b67689caaefd.jpg)

(https://uploads.tapatalk-cdn.com/20170830/b71c682bf3e2bc3000eee38e4898a27d.jpg)(https://uploads.tapatalk-cdn.com/20170830/73202b8471daec2eea878307b76cf0c7.jpg)

The smaller one is the original

(https://uploads.tapatalk-cdn.com/20170830/22f560e4327153367e8f5288876699c2.jpg)(https://uploads.tapatalk-cdn.com/20170830/4e4e5c007d3fb453790334e59eafa8d8.jpg)(https://uploads.tapatalk-cdn.com/20170830/0de849fd8e46384789dd9c7145de8c9b.jpg)

He then match ported them so the internal diameter would match the internal ID of the CR s and the ID of the CV boot there was about a 6 mm difference between the two (https://uploads.tapatalk-cdn.com/20170830/9e1b091d05433f9ad34d7a1d2c6a6dcd.jpg)(https://uploads.tapatalk-cdn.com/20170830/1dd462420862f61f5f76470535540bbe.jpg)

This is the first of the four the other three are yet to be made but I'm pretty happy with the way it turned out (no pun intended)

After this the adapter brackets for the rear sets will be made up


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Aug 31, 2017, 06:25:35
Looks sweet! Nice luxury to have your own personal machinist :)


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Aug 31, 2017, 08:57:36
The old man gets us out of some serious binds im lucky he loves it as much as i love bikes

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 01, 2017, 07:23:33
(https://uploads.tapatalk-cdn.com/20170901/1437691e5476caaf763d54d769992273.jpg)(https://uploads.tapatalk-cdn.com/20170901/1437691e5476caaf763d54d769992273.jpg)

Well that's done old mans punching out some professional work. I'm going to have to learn the lathe and mill.


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: dakine_surf on Sep 02, 2017, 07:09:30
Beautiful machining... your dad is a talented man... is he running CNC or Manual?


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 02, 2017, 07:14:54
Beautiful machining... your dad is a talented man... is he running CNC or Manual?


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Manual lathe and mill

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: dakine_surf on Sep 02, 2017, 07:17:35
Manual lathe and mill

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Hell yeah!  Such a lost art manual milling and the lathe, Really appreciate you sharing!


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 02, 2017, 07:35:22
Hes going to fabricate the adapter brackets for the R6 rearsets next. Hopefully when i get home i can piece most of it back together

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 03, 2017, 07:44:54
Has anyone on here run the CR 29's on a cb 750 ? im just wondering do i need to change the petcock at all to provide more fuel or is the stock petcock fine ??

I just purchased new CV boots as the rubber had perished on my old ones which were cracked. It's my day off tomorrow Im trying to work out what else is left to purchase.

I know I have to customise the front brake line to allow for the clip on risers, but I will wait until i can take the whole bike to the shop just to ensure the lines sit nicely.

I still need to find some small LED or projector lights to mount into the custom front fairing i want to make.

Still also need to work out what size sprockets front and back will be best
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: esmoojee on Sep 03, 2017, 13:37:01
Stock petcock will be fine.  No need to change it. 
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 03, 2017, 21:22:33
Stock petcock will be fine.  No need to change it.
Sweet one less thing to do, just need to nut out the mounting point for the damper. I looked at mounting it of the steering stop at the front but the damper is too long. 

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 04, 2017, 07:05:46
Finally found some 2" 10w LED i bought 3 1 with 25 degree spread the other 2 with 45 degree spread, hopefully they work with the front fairing i want to make

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 09, 2017, 03:15:27
so this is where I'm heading with the front fairing

this particular one is actually the front mud guard of some old bike with the windscreen being the visor from an old helmet

so Ive already ordered the 3 LED spot lights then when I get home I'll have to work out if im goint to make it myself out of fiberglass or try and find a fender

ill probablly stand mine up a little more at the top rather than having it roll back so much but I really like this idea very unique
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 09, 2017, 21:24:46
Back brake caliper pistons arrived in the mail (https://uploads.tapatalk-cdn.com/20170910/a9fdc91a36d14b767a707eefa5408f58.jpg)

Now i have everything i need to finish rebuilding the brakes

Hopefully the LEDs will arrive soon, ill he pretty happy if its all there waiting for me when i get back home



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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 10, 2017, 02:38:52
So this is the beginnings of the prototype    for the rearset adapter plate

(https://uploads.tapatalk-cdn.com/20170910/494df74e3e7ce996ca226fd3fd49b3a5.jpg)

See how it goes im thinking once its completed getting them anodised black

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 10, 2017, 18:56:47
So got a few more progress shots from the old man.

Before he could begin the prototype he had to make a fixture to secure the unusually shaped bracked(https://uploads.tapatalk-cdn.com/20170910/1625da193ab186e7bb4b8dd3c4b23859.jpg)

Then based on the wooden template i made for him he penned the shape into the aluminum
(https://uploads.tapatalk-cdn.com/20170910/15f9a119f095854a924ca1fbbf0228e2.jpg)

This is how he got the radius or the curve on the ends i think he may have just purchased this for the job

(https://uploads.tapatalk-cdn.com/20170910/05a93ec5fcfa410fa5917c917578a819.jpg)

(https://uploads.tapatalk-cdn.com/20170910/0042d4a997bafd2cd0b282cfd79ea42d.jpg)

Its still pretty rough he may need to see the frame so we can better run with the angles of the frame (https://uploads.tapatalk-cdn.com/20170910/55fe52cc8d9d80e8bf6fed4152e05013.jpg)

This is where the art of fabrication patience and perseverance comes into play

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 11, 2017, 06:44:34
So we've modified the design (https://uploads.tapatalk-cdn.com/20170911/6f3b931f98665eb0f4b9e7390dee54f0.jpg)(https://uploads.tapatalk-cdn.com/20170911/be1acdd350c729d6f126ad4a96b60d2e.jpg)

This new adaptation on the original template will slim the bracket down to look a little cooler

(https://uploads.tapatalk-cdn.com/20170911/3a7c93943ed7259673416acb74474386.jpg)

Steady steady

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Sep 11, 2017, 10:07:12
Definitely envious of you having your personal machinist, looking good! I've seen some cut down and re-drilled the original mounts but custom is of course nicer.


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: CrabsAndCylinders on Sep 11, 2017, 17:55:29
Definitely envious of you having your personal machinist, looking good! I've seen some cut down and re-drilled the original mounts but custom is of course nicer.

Yeah, custom is nicer and it's also a shame to much up the originals when some guys need them for restoration.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 12, 2017, 04:06:52
Yea once ive finished the build ill be selling off all the original fairings forks wheels and whatever else came of so that someone who's doing a resto can use it

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 12, 2017, 21:47:11
So some goodies arrived in the mail, the wifey was good enough to send me a few shots
(https://uploads.tapatalk-cdn.com/20170913/49376a54f83f1c68a2be0d88ce17a181.jpg)
(https://uploads.tapatalk-cdn.com/20170913/e692615747bdbfe85804378b2f783e6d.jpg)

New CV boots will hopefully create an air tight seal around the new CRs they cant be any worse that the old ones that were all cracked and perished

(https://uploads.tapatalk-cdn.com/20170913/a74e1021870db3cb68546db736d4aaaf.jpg)(https://uploads.tapatalk-cdn.com/20170913/3b377d2df0f6f0d3894491fc0ac9f906.jpg)(https://uploads.tapatalk-cdn.com/20170913/a84beead99779cd17dca4f2e19e676bb.jpg)(https://uploads.tapatalk-cdn.com/20170913/5269c88118477b918f2237c7e12bd236.jpg)

These are the 3 LED lights hopefully they work well with the front fairing im trying to dream up

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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 14, 2017, 04:27:26
So to say I'm pleased with the prototype would be a vast under statement ...it surpassed all my expectations (https://uploads.tapatalk-cdn.com/20170914/a5ccc49b670c7dec6fc2d3ae02c5fa6d.jpg)

I'm seriously stoked so the real deal is going into production now

(https://uploads.tapatalk-cdn.com/20170914/446659270a63dc7a8b22c97c86554713.jpg)

Mark up (https://uploads.tapatalk-cdn.com/20170914/d9b0663f302b6c53c1ffffea1eff8722.jpg)

(https://uploads.tapatalk-cdn.com/20170914/1d54c663374bff82f36b741c93f262dd.jpg)

The rough cut ...now the hard part I'm not too sure how much the old man will get done but based on the prototype it will be worth the wait


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 15, 2017, 07:48:14
So had some more progress on the final pieces

(https://uploads.tapatalk-cdn.com/20170915/1bb2658969346906597ddef41c307a68.jpg)

(https://uploads.tapatalk-cdn.com/20170915/cfc71cb0e736474398c86433eedfad1b.jpg)

(https://uploads.tapatalk-cdn.com/20170915/b3726a5fe82e579cd273eeb867795387.jpg)
(https://uploads.tapatalk-cdn.com/20170915/cba6784b71fd70e5094f7094a19fc38f.jpg)

(https://uploads.tapatalk-cdn.com/20170915/38ca4c3fa9fc47a58a08171f5b96ad57.jpg)

This is as far as the job has progressed, but I'm more than happy to wait.

Had anyone on here put the 900 cams in their 750 I'm just wondering how much it's going to change the performance coupled together with the CRs and the 4into 1


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: esmoojee on Sep 16, 2017, 00:21:48
Iíve done it, it does help a little but honestly Iíve already outgrown my 750. If I could Iíd gusset my frame and throw in a 1100f motor. Funds prevent me from such an endeavor.  :(
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 16, 2017, 00:32:09
that's alright I was just hoping for a little more poke around the street, if i want to go real fast that's what the R1 is for  ;)
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 16, 2017, 00:32:56
but seriously your bike looks trick, i love the rear swing arm
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 16, 2017, 04:58:21
Ok so the majority of the hard work is done

Just need to tap the holes for the rear sets to bolt onto and also work out the spacer size to put to accomodate for the oem bolts

(https://uploads.tapatalk-cdn.com/20170916/bdb85c344b29143d10cdaba7819dae74.jpg)(https://uploads.tapatalk-cdn.com/20170916/f9f9d09c6f9efd5f81a08f74b8b5f3f1.jpg)

Looking very cool


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 18, 2017, 07:48:47
Well I'm stoked the holes have been tapped and the rear sets bolted on... now I'm in two minds as to whether or not to get them anodised they look pretty good as is I may have to do a dry run.

(https://uploads.tapatalk-cdn.com/20170918/87fa490ce3d095bef5c987e05c60e431.jpg)(https://uploads.tapatalk-cdn.com/20170918/87fa490ce3d095bef5c987e05c60e431.jpg)

Only another two weeks and I can put these bad boys on

My brother also came through with the goods with the decal for the side of the tank

(https://uploads.tapatalk-cdn.com/20170918/e2084ffa59c534162c30cf1fc606b3c3.png)

Slowly slowly she's all starting to come together

Have to do some panel work I think when I get home among other things


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: Cookie on Sep 18, 2017, 11:38:40
I'd see about centering the wing on that logo: it'd look more balanced. Otherwise it just kind of looks like a decal saying "Franken" was tacked on to original. My $0.02.

They're pretty slick otherwise though; I love that your brother was able to match the font so closely to original
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: CrabsAndCylinders on Sep 18, 2017, 14:53:57
Damn, those brackets look fantastic!
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 18, 2017, 17:41:44
Damn, those brackets look fantastic!
Cheers I'm looking at what needs to be done to convert the mill to a CNC , hopefully we can design and replicate some of his work

When I get home I'll see how it looks maybe I'll just anodise it clear


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 18, 2017, 17:46:57
I'd see about centering the wing on that logo: it'd look more balanced. Otherwise it just kind of looks like a decal saying "Franken" was tacked on to original. My $0.02.

They're pretty slick otherwise though; I love that your brother was able to match the font so closely to original
Yea when it's in the middle it just doesn't sit right with me so it will have to look tacked on

Next challenge is getting the paint to match and also getting him to replicate the blue stripes , and work out how to / whether or not to strip the front and rear fairing


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: CrabsAndCylinders on Sep 19, 2017, 01:36:19
Yea when it's in the middle it just doesn't sit right with me so it will have to look tacked on

Next challenge is getting the paint to match and also getting him to replicate the blue stripes , and work out how to / whether or not to strip the front and rear fairing


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I wouldn't move it to the middle but rather about 1/3 of the way from the front.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 19, 2017, 03:18:03
I wouldn't move it to the middle but rather about 1/3 of the way from the front.
Spoke to my brother he will make up a sample I'll compare the two


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 21, 2017, 17:16:16
Can anyone tell me what the original front and rear sprocket ratios were on the dohc 750s I want to get new ones but I'm not at home to count the teeth also how many links in the chain ?? Cheers in advance


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: Cookie on Sep 22, 2017, 11:19:28
Can anyone tell me what the original front and rear sprocket ratios were on the dohc 750s I want to get new ones but I'm not at home to count the teeth also how many links in the chain ?? Cheers in advance


Yup!
Taken directly from the Honda Factory Service Manual, 1981 Addendum (there were no driveline changes in 1982):

CB750F and K ran 18 Front/46 Rear (2.555:1 ratio) with a 108 link, #530 chain.

CB750C was 18/43 (2.388:1) with 106 link, #530 chain (loses some acceleration, but better for cruising/touring).

 I went to a 17/40 combination with a 106-link chain on my 750C. Almost the same ratio (within 1.5%), but the smaller sprockets were on sale and saved me about/40. Also, it was cheaper to buy a 110 link chain and shorten it, than to buy a 106-link.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Sep 22, 2017, 16:15:38
Yup!
Taken directly from the Honda Factory Service Manual, 1981 Addendum (there were no driveline changes in 1982):

CB750F and K ran 18 Front/46 Rear (2.555:1 ratio) with a 108 link, #530 chain.

CB750C was 18/43 (2.388:1) with 106 link, #530 chain (loses some acceleration, but better for cruising/touring).

 I went to a 17/40 combination with a 106-link chain on my 750C. Almost the same ratio (within 1.5%), but the smaller sprockets were on sale and saved me about/40. Also, it was cheaper to buy a 110 link chain and shorten it, than to buy a 106-link.

Awesome I think my rear hub is a k anyway as it's a spoked rim with a disc brake, the original rim was a cornstar and it actually runs a different sprocket I was a bit devo as I was going to reuse it

If you change to a lighter chain say a 520 does that effect the sprockets you can use ?


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: Cookie on Sep 22, 2017, 21:39:56
Yea it does. 520/530 are both 5/8" long between the links, I believe 520 is narrower (thinner). Might have concerns fitting on stock-sized sprockets (but I've never tried).
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: 1fasgsxr on Sep 25, 2017, 13:17:30
If you run a 520 chain you have to run 520 sprockets
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 04, 2017, 23:44:24
So got back from work and decided after a red eye I would try to work in the bike... apparently this was not such a good idea, thought I would tackle the caliper rebuild

(https://uploads.tapatalk-cdn.com/20171005/6426be01c585525bd9bfa33361b0f672.jpg)

So these were the original pistons pitted, scratched and rusted

(https://uploads.tapatalk-cdn.com/20171005/6e6ee633cdc43ae25b68d6cfb108b067.jpg)

Here are the new ones that arrived

First I installed the rubber seals in, There is a thicker one that is inserted into the lower groove

(https://uploads.tapatalk-cdn.com/20171005/e444cec0f99fa8cc0fe20ca4de8914c3.jpg)(https://uploads.tapatalk-cdn.com/20171005/62c7b557240fe25b3c32c238b9e27a3b.jpg)

Through great skill and mastery I somehow managed to twist the seal as I installed it, after a little cursing and persistence I untwisted it.

I then installed the smaller seal (https://uploads.tapatalk-cdn.com/20171005/b69e55b6f3c8dd4ca4701fb673c33e83.jpg)

Then repeated for the other side (https://uploads.tapatalk-cdn.com/20171005/049e78520060688ddb3c914514180cc3.jpg)

I then put a little grease on them

(https://uploads.tapatalk-cdn.com/20171005/9cbc9338a364d1401e095973367436e1.jpg)

Next I replaced the bleed nipple (https://uploads.tapatalk-cdn.com/20171005/74948aa612d52d75c794cfb2030b257d.jpg)(https://uploads.tapatalk-cdn.com/20171005/e19f10e7550d63cdd823add9eb728b86.jpg)

Then I installed the rubbers and hollow pin (https://uploads.tapatalk-cdn.com/20171005/805ff67b91d755cd306a4147c6d1e57a.jpg)

Then this is the moment where I totally fucked up

(https://uploads.tapatalk-cdn.com/20171005/92b0db7cccdb8c055479c17dae4bd305.jpg)(https://uploads.tapatalk-cdn.com/20171005/9154a13a5d0a94bb3dffca060c47f2ed.jpg)(https://uploads.tapatalk-cdn.com/20171005/bbb74a7c1b840cd719e8f1ebbc98fc61.jpg)

Yep put the pistons in the wrong way didn't I .... face palm moment... so being a kid raised on magyver I thought to my self what would he do... so I tried connecting the old rear brake master cylinder and for some reason I can't get the pistons to move out ... currently at an in pass.

So rather than give you turned my attention to getting the motor back in the frame, as I moved the stand the motor fell off and this happened

(https://uploads.tapatalk-cdn.com/20171005/f1e37fd17b692681c1d03e0e1c315641.jpg)

I'm hoping it still seals otherwise I'll be in need of someone to weld then machine it ... not really what I was hoping for

In addition I scratched the engine paint a little luckily it's on a side cover that can be removed and painted

I tried laying the engine over (https://uploads.tapatalk-cdn.com/20171005/4de104b4ff3e56abe061ec81f4a51504.jpg)

But by myself I'm one arm short of being able to put it back in I think I'll have to wait for some assistance ... unfortunately wifey is about 1 week from due so my number one apprentice is off

Another thing I noticed I need to replace these bolts that hold the engine cover on (https://uploads.tapatalk-cdn.com/20171005/a07b7cbb791a6531b204be298236c42b.jpg)

Does anyone have a part number or know the proper name for these ?


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: hillsy on Oct 04, 2017, 23:55:19
You dont need to replace the entire bolt - you just want new rubber grommets for them. You should always replace these grommets if you are replacing the gasket as they tension the cover down to make it seal.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 05, 2017, 00:23:07
Thanks Hillsy, Do you have a part number for the gromit or know exaclty what its called so i know what to order online ?
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: hillsy on Oct 05, 2017, 01:51:26
Number 9 in this schematic - they are called mounting rubbers - Honda part number is 90541-425-000


(https://images.cmsnl.com/img/partslists/honda-cb750f2-1982-c-germany-cylinder-head-cover_bigma000096e01_0eb4.gif)
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 05, 2017, 02:17:21
you are a god dam legend
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 05, 2017, 02:35:29
order placed cheers Hillsy
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 05, 2017, 04:09:22
Ok so I couldn't let it beat me so I concocted a plan on how to get these pistons out

So first I connected the reservoir for gsxr front calipers

(https://uploads.tapatalk-cdn.com/20171005/78d6edaaad95f6786d5c5d3dd79098b5.jpg)

Then I proceeded to purge the line of air first I disconnected the line from the caliper it took a little but the fluid started coming through.

Once I had fluid there I kept the lever down and reconnected the line to the caliper

(https://uploads.tapatalk-cdn.com/20171005/b1e5b8d4d8367ef4f095660a42eb2ed5.jpg)(https://uploads.tapatalk-cdn.com/20171005/b1e5b8d4d8367ef4f095660a42eb2ed5.jpg)

Next I connected a clear line to the bleed valve and waited for the air to purge (https://uploads.tapatalk-cdn.com/20171005/0ea2b564c090565553186ed41cbba713.jpg)

Then I kept at it till there was movement on the pistons (https://uploads.tapatalk-cdn.com/20171005/ac0458c51f9510afced50f21f02252dc.jpg)

I just kept resistance on both the pistons so they came put evenly

(https://uploads.tapatalk-cdn.com/20171005/126c9ac95fa3449a1c101222099ceba6.jpg)

Success and now to undo my bad work and reinsert the pistons the correct way

(https://uploads.tapatalk-cdn.com/20171005/628d56a9ed4501e8eb1722a7e95d2e3f.jpg)

Ok so next I had to put the pads back in  each held in place with two pins (https://uploads.tapatalk-cdn.com/20171005/ddc493c052286c12dc2041c208c6207c.jpg)
(https://uploads.tapatalk-cdn.com/20171005/c48395eb9585224a167b706ae703d698.jpg)

Once the pins are in there is a retaining plate that bolts into place
(https://uploads.tapatalk-cdn.com/20171005/be1d6840befdda75a15a1296e186860c.jpg)

I then connected to the arm that secures it to the rear axle (https://uploads.tapatalk-cdn.com/20171005/66f5dddd37a308c5e9f8dfa8d5a2d5e7.jpg)(https://uploads.tapatalk-cdn.com/20171005/82a439875d28efd8f986a7705944b62b.jpg)

(https://uploads.tapatalk-cdn.com/20171005/661e51fc5001f4e1126775e48c778f3c.jpg)

Job done


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 07, 2017, 21:59:26
Ok so last night I managed to get down to the old mans with the frame so we could make up the final spacers required to fit the rearsets and also to make sure the brackets didnít interfere with any of the bolts ( which they did a little)
(https://uploads.tapatalk-cdn.com/20171008/ff0412d3381152c89743bfeb148fdc13.jpg)(https://uploads.tapatalk-cdn.com/20171008/3fb0ddfdec18aa7cd68f7b833e77fa8c.jpg)

So first we made sure the holes were in the right place.. the pressure was on as I was the one who made the template so if she was out it was on me, luckily she fit just like a bought one.

Once the brackets were finished n place we measured to see how big the spacers would need to be
(https://uploads.tapatalk-cdn.com/20171008/5cfedf7fda34924e346b79315bec8e40.jpg)

The right side required a larger spacer for the bracket as the left side sits just about flush

(https://uploads.tapatalk-cdn.com/20171008/aec8cac6dd6b3d577ae0e84628375c73.jpg)

We turned up the spacers for in between the rear set and the brackets first as they would be the same the two tops  and then the two bottom spacers

(https://uploads.tapatalk-cdn.com/20171008/a9adb4f1494be9afd21355e4f1160bbd.jpg)

Top spacer done

(https://uploads.tapatalk-cdn.com/20171008/03a386723db8b4049bc467732ca6187d.jpg)

Top and bottom complete

(https://uploads.tapatalk-cdn.com/20171008/131b9b23262a7e06232b4c59461cb3ba.jpg)(https://uploads.tapatalk-cdn.com/20171008/a0881a43e00a1a55aee700ca2310fac9.jpg)(https://uploads.tapatalk-cdn.com/20171008/f734d1059930cb3043a6ef9549d6d42e.jpg)

This was the spacer for in between the frame and the bracket

(https://uploads.tapatalk-cdn.com/20171008/f5cd7cb8d7692e0bdb1791bd7c3f89fb.jpg)
(https://uploads.tapatalk-cdn.com/20171008/ee7dcdcba524f218a3c9ee300a3c5f18.jpg)
(https://uploads.tapatalk-cdn.com/20171008/015ed3135537380b82bddd80155c24f3.jpg)

Right side complete next issue was that the swing arm bolt was too long so it needed to be shortened and rethreaded... this is always a tense moment as weíve found itís really hard to undo or put back what you mess up :/

(https://uploads.tapatalk-cdn.com/20171008/0b430ca34a1eca4527ed15f6b889062c.jpg)(https://uploads.tapatalk-cdn.com/20171008/72eaa1c489afe3867fbdc447d48ec71f.jpg)

Fist the old man established the thread size, this then dictates the gearing of the lathe.

(https://uploads.tapatalk-cdn.com/20171008/5a15c10b587dad7f3c43c5be21c0eab9.jpg)

Then he did the scratch pass and we double checked to make sure we were on point... came up all good

(https://uploads.tapatalk-cdn.com/20171008/c94706e84fc515f6006f44e48cf791f5.jpg)

Clearances were tight

(https://uploads.tapatalk-cdn.com/20171008/158666ae6b6c0e83984e38dda2a00b42.jpg)
(https://uploads.tapatalk-cdn.com/20171008/69f751c7ff121e0f9404d5142ca09a26.jpg)
(https://uploads.tapatalk-cdn.com/20171008/fcdd0562384e784da322414200179a3a.jpg)(https://uploads.tapatalk-cdn.com/20171008/e33c252ccb810b64569823e5739a0282.jpg)(https://uploads.tapatalk-cdn.com/20171008/56e9daf55b85e2e6f1cd4f3ec5bd8cd4.jpg)

So Iíve decided to leave it silver I think it would be a shame to anodise it black and not have the old mans craftsmanship stand out

...now Iíve got to work out how to get this engine in :/


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: Cookie on Oct 08, 2017, 00:17:06
Well done; those rearsets are looking boss!
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Oct 08, 2017, 04:06:55
Looks slick man. Out of curiousity, why not continue the chamfer around the entire bracket? Noting seems to be mating that far out, and it may look a little cleaner. Just thinking out loud lol.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 08, 2017, 05:23:13
Looks slick man. Out of curiousity, why not continue the chamfer around the entire bracket? Noting seems to be mating that far out, and it may look a little cleaner. Just thinking out loud lol.
Because thatís the way the rear sets are chamfered, they are not chamfered around where the bolts are


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 08, 2017, 05:38:50
Ok so I decided to do the install of the engine by my lonesome...

First I propped the engine up on some blocks of wood I had laying around in the shed
(https://uploads.tapatalk-cdn.com/20171008/fe88406e7a0ad5125d4d120f935bbe7a.jpg)(https://uploads.tapatalk-cdn.com/20171008/4334cb8435819de8f69c5ef3b9a8800b.jpg)

Next I wrapped some rags around the frame in anticipation of me bumping and scratching it

(https://uploads.tapatalk-cdn.com/20171008/109458d0859a961259b06aba962554fb.jpg)(https://uploads.tapatalk-cdn.com/20171008/5d967848d044d0c55da92f67fe22477c.jpg)

The next bit I was unable to photo as I had my hands full, basically what I did was place the frame next to the engine then I sat my ass down on the floor and slowly shimmied it into position

(https://uploads.tapatalk-cdn.com/20171008/160f3ef4e1f98cca3729344baa2460a4.jpg)(https://uploads.tapatalk-cdn.com/20171008/047da9bf65ec2774aa7c57d85b17e7f2.jpg)

Then I went about tapping in all the engine mount bolts

(https://uploads.tapatalk-cdn.com/20171008/5ea5c5765977ea2ab1d401958eb92964.jpg)(https://uploads.tapatalk-cdn.com/20171008/bef952fd219ed785dbe8ba4d9c7c24e6.jpg)(https://uploads.tapatalk-cdn.com/20171008/21a057a07527aef08c2e54492feb6ccf.jpg)(https://uploads.tapatalk-cdn.com/20171008/c89026f65fa27325270ef65f92d4aa65.jpg)

This was the top engine mount at the back

(https://uploads.tapatalk-cdn.com/20171008/f7a01958b2babdad4f70145532069f40.jpg)(https://uploads.tapatalk-cdn.com/20171008/8846a99e37d8867124dbc2f7514b9447.jpg)

I then replaced the part of the frame that I had previously removed when taking out the engine

(https://uploads.tapatalk-cdn.com/20171008/5c4274087f62a8d64978298a31838b82.jpg)(https://uploads.tapatalk-cdn.com/20171008/e9c6b3c8c86558eff1e0071c6d61d49f.jpg)

Then onto the front engine mounts

(https://uploads.tapatalk-cdn.com/20171008/da0db1230aef84cbb5bbc14fa8a8b221.jpg)(https://uploads.tapatalk-cdn.com/20171008/fd90f43c8fc029ca8a0bc5376d3e07bf.jpg)
Rear sets and swing arm

(https://uploads.tapatalk-cdn.com/20171008/7e05a7d16600cac2d4a275bce3895b98.jpg)(https://uploads.tapatalk-cdn.com/20171008/379d6d63410ca9b96739e961915ee7d1.jpg)

Rear wheel, caliper and brake support

(https://uploads.tapatalk-cdn.com/20171008/57700cdb8b5b82418caabec8c148fd41.jpg)

I put in the centre stand to make it easier to get the forks in

(https://uploads.tapatalk-cdn.com/20171008/f24622b53d5747723b0c595d036fb715.jpg)

Then just for shits and giggles I put the tank and seat pan on

(https://uploads.tapatalk-cdn.com/20171008/4d93816db214702042b2864def69d3f1.jpg)

Iím not 100% on the seat pan, going to have to mull it over, also I still need a rear sprocket, the rear disc need to be drilled and all associated brake lines need to be made up... although brake lines will be some of the last things I do.

Tomorrow I will see how the carbs match up, then perhaps look at the front fairing and seat pan

At least she rolls now


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: jag767 on Oct 08, 2017, 08:22:42
Ahhh you mirrored it, very cool!
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: Cookie on Oct 08, 2017, 10:46:28
My Gord, thats pretty! Nice work, man.
I really dig that seat pan
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 08, 2017, 18:18:57
My Gord, thats pretty! Nice work, man.
I really dig that seat pan


The rear of it I like but the part I would sit on just doesnít gel with me for some reason

(https://uploads.tapatalk-cdn.com/20171008/2a78e88a8177c7da7f781924d4740959.png)

Someone flicked me this for inspiration it ties in beautifully with the tank, unfortunately my fibreglassing skills are at -100 amateurish on a good day


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: esmoojee on Oct 09, 2017, 02:44:51
Looking really good!!! Youíre probably gonna have to relocate the kickstand. Hate to be the bearer of bad news but the bike looks dope!

Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 09, 2017, 05:10:43
Ok so today I thought I would try my hand at making the seat pan again...

Brace yourselves

(https://uploads.tapatalk-cdn.com/20171009/bba21afcc35a73a2cab60c039db92473.jpg)(https://uploads.tapatalk-cdn.com/20171009/51600f0e2b8119385ad7897f532de9da.jpg)

So first for the glad wrap this is what I should have done the first time it pulls close to the contours of the frame and tank... instead of me putting mesh the first time, this was a fuck up as the fibreglassing didnít form to the frame properly

(https://uploads.tapatalk-cdn.com/20171009/8e86cdb141048400a847a22cf5dc6f58.jpg)

Next I tried to make a template out of thin cardboard

(https://uploads.tapatalk-cdn.com/20171009/10a2624029368c6bd5c1c218e17e34f4.jpg)(https://uploads.tapatalk-cdn.com/20171009/4913bc7a5861632360b9da5ec3810e4a.jpg)(https://uploads.tapatalk-cdn.com/20171009/ca62cc16d2d8c82eb59d99782efadda2.jpg)(https://uploads.tapatalk-cdn.com/20171009/e8b315e2e3295dc1933ae6cacc6b9abb.jpg)(https://uploads.tapatalk-cdn.com/20171009/4b978eb2b01e14c0f6ea805115aad3fb.jpg)

Unfortunately in hindsight I didnít glad wrap the frame enough Iíve already seen some spots where the resin made it onto the swing arm and subsequently wrecked the paint ... hopefully itís only on the swing arm, I can deal with that fingers crossed itís not on the frame.

(https://uploads.tapatalk-cdn.com/20171009/0c625e696708efc355790cdfd92f655f.jpg)(https://uploads.tapatalk-cdn.com/20171009/66c0d7ebf9c918f6b45a9ea710d5fa4b.jpg)

Then I laid the fibreglassing matting in place and painted the resin on

(https://uploads.tapatalk-cdn.com/20171009/3fd096754f320b314933f16d8941b776.jpg)(https://uploads.tapatalk-cdn.com/20171009/59654c638e81843708282fc1159824a1.jpg)(https://uploads.tapatalk-cdn.com/20171009/b67ec58a752a93adc3c65b04390cda88.jpg)(https://uploads.tapatalk-cdn.com/20171009/4ba64d2560a8751e8dfb07ccd2a9d307.jpg)(https://uploads.tapatalk-cdn.com/20171009/231852598f6b5b7ebfba8a77880d3894.jpg)

Now to let it dry then inspect how close or far I am from where I want to be, hopefully it comes up a little better than my first attempt


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 09, 2017, 05:13:48
Looking really good!!! Youíre probably gonna have to relocate the kickstand. Hate to be the bearer of bad news but the bike looks dope!

What makes you say Iíll have to relocate the kick stand ? The new rear sets ? :/ hmmm more modifications


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: LightsOut on Oct 09, 2017, 08:08:18
Looks really good assembled! I liked the seat you had, but fingers crossed the second one turns out the way you want. As for kickstand I guess rearsets could interfere? or height could be wrong with the changed angles?


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 09, 2017, 08:20:06
Yea she looked good from afar but was far from good

(https://uploads.tapatalk-cdn.com/20171009/e0f1046872aaf43926249d3938170915.jpg)(https://uploads.tapatalk-cdn.com/20171009/c6a32e019f591d8a04c9842b031d6a8a.jpg)

Because of the mesh I had to use big so it would sit properly

(https://uploads.tapatalk-cdn.com/20171009/f4f434694f5a7e943f54fd735f879d1a.jpg)
(https://uploads.tapatalk-cdn.com/20171009/3ab421cc324e9ee9e9a5b6cf5b5acc2c.jpg)(https://uploads.tapatalk-cdn.com/20171009/f1af86e8b6830b3f803dde2214f1b518.jpg)(https://uploads.tapatalk-cdn.com/20171009/2b98484835fcb93f07a320489a07bfb3.jpg)(https://uploads.tapatalk-cdn.com/20171009/443c35112ee69c3d107cc9d49ff59e4d.jpg)(https://uploads.tapatalk-cdn.com/20171009/de04ad6883e58fa74a341c5083d8ae91.jpg)

New one is a slightly more refined version of the first not too different as I really liked the shape of the original just not the finish


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: esmoojee on Oct 09, 2017, 13:50:12
Yea, I think they may be in the way. I had to move mine.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 09, 2017, 18:35:36
Yea, I think they may be in the way. I had to move mine.

Have you got any photos of how and where you moved your kick stand, Iíd be interested to see how those before me dealt with this issue... to be honest it hadnít even crossed my mind until you guys brought it up.

I had noticed the angle of the kick stand changed because the bike is now lower but i didnít even contemplate the fact it might not return to the correct place... :/

Iíll try to sort this seat pan before tackling that issue, one thing at a time otherwise Iíll become overwhelmed.


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 09, 2017, 22:40:26
Ok so the resin dried

(https://uploads.tapatalk-cdn.com/20171010/5552463964b72fd3bff506554430a0a2.jpg)
(https://uploads.tapatalk-cdn.com/20171010/11ee4120107d9c98a921966f343ac15b.jpg)

So I grabbed a marker and drew the lines I wanted to cut

(https://uploads.tapatalk-cdn.com/20171010/1c647d86f6d460dac8fc4fced673f021.jpg)(https://uploads.tapatalk-cdn.com/20171010/7367ae912f4e143471205014545ee9ea.jpg)

I removed the seat pan and original mould ..(https://uploads.tapatalk-cdn.com/20171010/4badc9281f929d63110dd806c09f3e7a.jpg)(https://uploads.tapatalk-cdn.com/20171010/999e46ea1918d20d8494eff339b5560b.jpg)

Unfortunately my glad wrapping wasnít as effective as I would have liked it to be...rookie error to be fixed once fibreglassing is complete...

(https://uploads.tapatalk-cdn.com/20171010/6d66c192346aa63f7487c274979cdf02.jpg) here is the new and old side by side for comparison, no one would have known the difference in quality except me, unfortunately that would have done my head in.

(https://uploads.tapatalk-cdn.com/20171010/d9aeb1497f9a15d2eae13428c249b9cd.jpg)(https://uploads.tapatalk-cdn.com/20171010/6742aa7fc218e26341758f52f9e3b69f.jpg)(https://uploads.tapatalk-cdn.com/20171010/63d0a4dbabf4c163037c0dfadd365baf.jpg)(https://uploads.tapatalk-cdn.com/20171010/ecd39a44a4404a167288ed8c1ebe934e.jpg)(https://uploads.tapatalk-cdn.com/20171010/9e88c704a36aea3e11d43e0e8e90a024.jpg)(https://uploads.tapatalk-cdn.com/20171010/dc243959e08d7bb619ca22679b515911.jpg)

Thatís how she sits now... there are a few spots that need to be built up and smoothed out.... so now Iíll wrap the frame up again and hit it round two, this time the plan is to get it as close to plum before just finishing it with bog as opposed to the bulk amount I used on the original




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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: esmoojee on Oct 10, 2017, 01:26:00
Here you go. I got a tc bros and had it welded further forward close to the front engine mount.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 10, 2017, 01:29:15
i love this bike, its badass
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 10, 2017, 01:36:39
i can almost see your damper set up, there are a few guys with CB750s on the forum Im on here and we are all scratching our heads on how exactly to mount that.

I looked at mounting it on the steering stop but when i turn the froks it looks like they will contact the damper.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 10, 2017, 18:17:54
So the finish on the seat pan was really rough and textured.

So what I did was just mix the resin and pour it on without Abby additional fibreglass matting

Iíll wait to see how it turns out, currently in hospital waiting room baby day today ... watch this space




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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: 1fasgsxr on Oct 11, 2017, 12:34:42
If you want it smooth you have to finish it the way you want and make a mold from the plug, then make your final product from your mold.  Or add a bunch of material to it and finish it . It will probably be heavy though if you go that route.

And good luck at the hospital !!
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: advCo on Oct 11, 2017, 12:45:44
First issue is with that chop mat. That stuff isn't meant for smooth finished applications. What you should use is 6oz biaxial cloth common for boatbuilding applications. I used 5-6 layers on the seat on my 360.

You have the right idea of using resin to smooth, however straight epoxy is not ideal to shape to a final form. West System makes a featherlight additive for their epoxy which is a powder you mix in that essentially turns it into a epoxy based version of bondo. This is the stuff you want to use to build up on the exterior, then sand down to get your final, smooth form.

6oz mat
(http://images.tapatalk-cdn.com/15/06/08/9298493359e661b579fb40c710f15ee8.jpg)

Seat after initial glass layup, finished off with a coat of epoxy w/featherlight additive.
(http://images.tapatalk-cdn.com/15/06/08/c3e55141e8823dc3fa4d5da548385171.jpg)

After a few coats of featherlight and lots of sanding
(http://images.tapatalk-cdn.com/15/07/13/9eb83d966c99f9cb295c7f605e9e9506.jpg)

I should note that with 5-6 layers of mat and quite a bit of epoxy filler, this seat pan only weighs about 3-4 lbs.
Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 14, 2017, 05:44:14
 Ok so still at the hospital but had to do a run home so stuck my head in to check out my handy work(https://uploads.tapatalk-cdn.com/20171014/72df6b4ee169e16b32e6cad973121425.jpg)(https://uploads.tapatalk-cdn.com/20171014/06b4a77eb9dde3978b900ed626bfe786.jpg)

The seat pan came up really nice, the resin seemed to self level


(https://uploads.tapatalk-cdn.com/20171014/3d3292d28ae843e0b922fffa4f1a8251.jpg)(https://uploads.tapatalk-cdn.com/20171014/c2491574997dcceddc81b7169854e150.jpg)(https://uploads.tapatalk-cdn.com/20171014/3ada47a8e7823685e5f4b9a2b188599e.jpg)

But I think your right Iím going to need the fibreglass cloth over the rear section so it finishes nicely.

(https://uploads.tapatalk-cdn.com/20171014/efcb15d1a25d810805ab066015572db2.jpg)

Iím just not sure if this transition to the tank works nicely or I need to tie it on some how, to tie it on will be very challenging I believe

I need a pros eye to nail it


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: Ant36 on Oct 14, 2017, 22:50:29
There is also stuff called quick fair that is used in marine applications for finishing. It's Like the west systems stuff but easier to use.


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 15, 2017, 04:41:41
There is also stuff called quick fair that is used in marine applications for finishing. It's Like the west systems stuff but easier to use.


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Nice because the smoother I can get it now the easier it is to finish later


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 18, 2017, 00:03:33
Ok back from our extended stay in hospital, mum and Jnr both home safe and sound..

So while they sleep I thought Iíd creep back into the garage to have another go at this seat pan

(https://uploads.tapatalk-cdn.com/20171018/874e2a9737273f61798903de58418289.jpg)(https://uploads.tapatalk-cdn.com/20171018/979b003d32208b87043d3c87e62e957c.jpg)(https://uploads.tapatalk-cdn.com/20171018/979b003d32208b87043d3c87e62e957c.jpg)

There were a heap of daggy bits hanging off it so I cleaned them up with the angle grinder

(https://uploads.tapatalk-cdn.com/20171018/ea70cc4ea59effa57972c000e88c8f8e.jpg)

To ensure the fibreglassing wrapped around the contour of the frame this time I sprayed  little contact adhesive to the seat pan first




(https://uploads.tapatalk-cdn.com/20171018/6d4b806be30b3ad0360f83ca6b5c815b.jpg)
(https://uploads.tapatalk-cdn.com/20171018/bf7c3c5949354990a824cc45155c4d06.jpg)(https://uploads.tapatalk-cdn.com/20171018/218e5684fe378a5fe46e5fa9eca70dac.jpg)

Once that was on I laid my fibreglass cloth

(https://uploads.tapatalk-cdn.com/20171018/89fad4c2807d97b19d732fd4e8d270ed.jpg)
(https://uploads.tapatalk-cdn.com/20171018/143e70ca234b7af99c25db7d09c44e92.jpg)
(https://uploads.tapatalk-cdn.com/20171018/e815d8fd867dae6c83ee088db11a9538.jpg)

Next I gave it a good coat of resin

(https://uploads.tapatalk-cdn.com/20171018/b9a43b82bcb02fa28024963ccb563283.jpg)(https://uploads.tapatalk-cdn.com/20171018/687072ff34733196d60af1b64b4a18f9.jpg)
(https://uploads.tapatalk-cdn.com/20171018/a01d628a2a02919fadc2d03dec9730a7.jpg)

This is how she stands while Iím waiting for the resin to cure,

Iíll give it a bit then see if it needs another coating, the seat itself is fine. Itís just the tail section I can see requiring a little more love... I wish I had of though of this before ... the old trial and error is quiet costly when your dealing with resin I think between this and my first attempt itís cost around $400 but I was set on doing it myself... thatís what experience costs you

Iíll still have to cut out a nook for the tail light led strip but that will be last



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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 19, 2017, 03:21:32
Fibreglassing the saga continues

(https://uploads.tapatalk-cdn.com/20171019/85ae9a7cbb8d35a821c3e71b47849c8b.jpg)
So it was time to man up and start sanding this bad boy back

(https://uploads.tapatalk-cdn.com/20171019/2f57f48043e9c0335e97176cf4ff9a09.jpg)

(https://uploads.tapatalk-cdn.com/20171019/cdd94ae6d7a2937cc0633bfeb72daa79.jpg)(https://uploads.tapatalk-cdn.com/20171019/e19526d224e5e1bacbf7fc7947720aa6.jpg)

Progress was slow

(https://uploads.tapatalk-cdn.com/20171019/af01b174c33a71388fff362f29426064.jpg)(https://uploads.tapatalk-cdn.com/20171019/396351da7dfc821d889f62f411a487a5.jpg)

I think my use of contact adhesive was a poor decision Iíve found spots that did not bond and I believe that is the reason why. Iíll chalk that one down to experience (https://uploads.tapatalk-cdn.com/20171019/a16a69e270fc5de6b6dfc714861d411e.jpg)(https://uploads.tapatalk-cdn.com/20171019/62cf243cd79353fc6a2a1cc49b4479db.jpg)(https://uploads.tapatalk-cdn.com/20171019/3bbe59efdf8f51ed39a08cd24a8a667a.jpg)

You can see it laminated, it could be a culmination of my poor fibreglassing compounded by the fact I used contact adhesive.

(https://uploads.tapatalk-cdn.com/20171019/822b1f96f0a56a0eef06b2b53921878b.jpg)(https://uploads.tapatalk-cdn.com/20171019/e5a9be0f2db4233aa7a166d8e07e67af.jpg)(https://uploads.tapatalk-cdn.com/20171019/7299a28db9c8f73bb704e7b0ff710383.jpg)

I sanded it back and got it as close to spot on as I could. Some of the edges werenít sharp so I decided to do another layer of fibreglassing
(https://uploads.tapatalk-cdn.com/20171019/f78dd88475117d55ae9779b99de0e026.jpg)(https://uploads.tapatalk-cdn.com/20171019/786ca3b3007076b4b0e8761934c82020.jpg)(https://uploads.tapatalk-cdn.com/20171019/c6af1eebe3e632e2740280d8ff185ccb.jpg)(https://uploads.tapatalk-cdn.com/20171019/51d0989e92138ccfbb24afc3cc6b3df1.jpg)(https://uploads.tapatalk-cdn.com/20171019/a05df76375bb7692413adab10cacb903.jpg)(https://uploads.tapatalk-cdn.com/20171019/a3a4f4128d9a2053d4520715a0d83237.jpg)

As I was working in the garage the postman came past

(https://uploads.tapatalk-cdn.com/20171019/7e4651e74ba7e872ef20a4fea4a52008.jpg)

Said Japan had me thinking Honda,

(https://uploads.tapatalk-cdn.com/20171019/46041531eb44dec96c4b12dabf404d6e.jpg)

It was the rubber seals for the engine cover bolts.

Probably be another hour or so before the resin cures the weather has taken a turn and itís become a little cold which will extend the curing time

I tip my hat to guys that make custom fairings... itís definitely an art, and I ainít no artist


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 22, 2017, 01:03:08
So Iím toying with the idea of putting a ridge on the seat pan to tie in with the ridge on the tank

(https://uploads.tapatalk-cdn.com/20171022/9b2f895df084a0f694697a9ed17ec723.jpg)
(https://uploads.tapatalk-cdn.com/20171022/9959ff45d9886f0dd1b99cfd77ff58cd.jpg)(https://uploads.tapatalk-cdn.com/20171022/2e7d825762969e82c859962051b1a4a8.jpg)(https://uploads.tapatalk-cdn.com/20171022/3acedd1111d3f25b4fe5871fe97c160c.jpg)(https://uploads.tapatalk-cdn.com/20171022/13a45eec3717f8ecc5d03183bd8cc1fc.jpg)

Iíve used cardboard as a template I was going to cut slots into it so the fibreglass resin goes through it and bonds to the surface below

A little unsure


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: innovativems on Oct 22, 2017, 01:30:12
if you can make it flow, might work out good with the tank.  But do not glass the cardboard.  Just build it up with glass.  Cardboard doesn't do wellbwith fiberglass resin


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 22, 2017, 06:09:16
if you can make it flow, might work out good with the tank.  But do not glass the cardboard.  Just build it up with glass.  Cardboard doesn't do wellbwith fiberglass resin


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why is that does the card board collapse with the resin ? Iím just not sure how I can get sharp lines

(https://uploads.tapatalk-cdn.com/20171022/5ccb50670849f8b6a3de802fc2f931ee.jpg)

I peeled the layers of a little at a time to get the rib fading out towards the back of the tail
(https://uploads.tapatalk-cdn.com/20171022/858628ff1e49cd81a4abd5f825e74435.jpg)

I cut some grooves in the cardboard so the resin will go through it

(https://uploads.tapatalk-cdn.com/20171022/3ee634b05eb18ab8e2b88bd58b2d08d2.jpg)
(https://uploads.tapatalk-cdn.com/20171022/bbd0d13af3f4e862a8f460b413020a5e.jpg)

I think Iím going to have to put a thin layer of bog over it to smooth it out

(https://uploads.tapatalk-cdn.com/20171022/fdb6b1cfd73bae8a2d8b2c82f75d4f81.jpg)(https://uploads.tapatalk-cdn.com/20171022/c29cba4efb00c74137e959998c15e301.jpg)(https://uploads.tapatalk-cdn.com/20171022/e735c1e914f027af6bbf77c05549cbd0.jpg)(https://uploads.tapatalk-cdn.com/20171022/b08ae4676328326c05ad4df17013c5b2.jpg)

I used a marker just to show me the lines. There not exactly where I want them yet, a little uneven I think on the left top

Oh well back to the shed I go


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: innovativems on Oct 22, 2017, 17:47:00
Fiberglass resin cures through a chemical reaction with the catalyst and creates heat during that process.  Cardboard may work but also stands the chance to collapse/be inconsistent with how the resin saturates it.  And if you plan to paint it at some point; any issues could rear their head down the road if there is an air pocket somewhere.  To build that up, you could use a long straind fiberglass filler and tape off where you want the hardines.  Honestly I think it looks good without the center being raised. 


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Title: Re: FRANKENHONDA II the 1982 DOHC CB 750F2 Build
Post by: cb250nproject on Oct 22, 2017, 18:59:09
   Well I took a punt on the cardboard

(https://uploads.tapatalk-cdn.com/20171022/56c376463178e39d7e925b7234f803c6.jpg)

I cut slot and drilled holes through it that I later injected the resin through

(https://uploads.tapatalk-cdn.com/20171022/aa85efd8cc3216c4b391823371983046.jpg)(https://uploads.tapatalk-cdn.com/20171022/8420e4ea66d8e50c6b455c52e7a980c1.jpg)(https://uploads.tapatalk-cdn.com/20171022/eadb2a37a1511194e6c339b9f0ee63e5.jpg)

There was a small void underneath the cardboard that I filled with fibreglass cloth

(https://uploads.tapatalk-cdn.com/20171022/a9b1aaa50135706300696bba0c5eac86.jpg)(https://uploads.tapatalk-cdn.com/20171022/e036781b0076007a6e1235d69c1f5c4d.jpg)(https://uploads.tapatalk-cdn.com/20171022/7f8d00ac3d46e84051c18404afe996eb.jpg)(https://uploads.tapatalk-cdn.com/20171022/ab3309b83bfebde14169c030dc107445.jpg)(https://uploads.tapatalk-cdn.com/20171022/2d32c09955b51cbef688983c8cbca136.jpg)(https://uploads.tapatalk-cdn.com/20171022/1876cb08d9974d137979ef83c9ed1383.jpg)

This is what I came into this morning

I had laid fibreglass cloth over the top of the cardboard also, I had excess resin also so I painted over the fairing to smooth it out the poured the rest where the seat will eventually end up and it smoothed it out a treat

Iíll go walk the dogs then when I return Iíll give it another layer of fibreglass and resin and square up the front of the ridge with the angle the back out the seat pan has.... then Iíll hit it with the sander again see what magic I can conjure up


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