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Blood Sweat Tears and Grease => Projects => Cafe Racers => Topic started by: CB MIKE on Aug 26, 2016, 13:45:16

Title: 81 CB 750C
Post by: CB MIKE on Aug 26, 2016, 13:45:16
Hello All,

New to the forum and the café scene. Just brought home an 81 CB750C yesterday. I have plans to convert to café/brat style, mostly cosmetic upgrades along with the standard tune up parts and any necessary repairs. I have been reading a lot about the different models and realize that I may have given myself more of a challenge going with the "C" model. Either way its in the garage now and I'm going to make it work for me.

Currently my to do list is as follows:
-Disassembly and deep inspection of components and hardware
-Remove, disassemble, & clean carbs
-Tighten cam chain (has THE knock)
-New plugs
-New consumables (filters etc.)
-Replace front brake pads (some pulsing at higher speeds) if that doesn't correct issue I'll move to replacing the rotors
-Build custom seat/fender
-Aftermarket tail light, head light, and turn signals
-Drag bars, grips, and eventually gauges.
... and I'm sure there are things I forgot but as the work progresses this list will grow

(PO recently changed oil, filter, starter and solenoid) I'll change the oil and filter eventually but for now its good

I am having a hard time locating a carb rebuild kit. I would like to get the randakks but for my model its sold out. The only others I have found so far are for the "K" models. Are these compatible as long as they are for the same-ish year and DOHC?

I appreciate the information that you all have put out there and look forward to this build. I will post pics throughout the process which may take time as funds are available so be patient. I am attaching a pic of my bike the day I picked it up and my inspiration Thanks
Title: Re: 81 CB 750C
Post by: cxman on Aug 26, 2016, 14:04:14
randakks is closed till sept 17 he has inventory its just not showing
Title: Re: 81 CB 750C
Post by: CB MIKE on Aug 26, 2016, 14:07:16
Awesome glad to hear it, I guess I have a few weeks to disassemble and clean them before I order the kit. Thanks
Title: Re: 81 CB 750C
Post by: BigNickel on Aug 26, 2016, 16:03:06
I'm also in the middle of a '81 750C build. Glad to see I'm not the only one trying to "tackle" this bike. I think they have great potential despite not being the most desired model. Yours looks super clean to begin with and I'll be following your progress for sure.

Cheers
Title: Re: 81 CB 750C
Post by: CB MIKE on Aug 26, 2016, 16:14:36
Thanks bignickel, it definitely has potential and I'm looking forward to the project. The bike has some surface rust here and there (unfortunately living in new England it's hard to not find any) other than that I was lucky. I got the bike from a Vietnam vet who took very good care of it and aside from a tune up its pretty mechanically sound. Well work through this together!
Title: Re: 81 CB 750C
Post by: CB MIKE on Aug 28, 2016, 16:09:00
So after the first weekend... new drag bars, grips, & mirrors on order. Rear end stripped and seat shaping has begun  (can't afford new right now so I'm working with what I have)

(http://uploads.tapatalk-cdn.com/20160828/647aa915e25d02e9217e8ffa9260f750.jpg)

(http://uploads.tapatalk-cdn.com/20160828/4fa1934bbcf376e6fb18352c289687e2.jpg)

(http://uploads.tapatalk-cdn.com/20160828/9573cf9622e64bd33149a123080c369a.jpg)

(http://uploads.tapatalk-cdn.com/20160828/c400509fc6efcf00a2a1300b1b5dc95a.jpg)


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Title: Re: 81 CB 750C
Post by: BigNickel on Aug 29, 2016, 08:21:25
Great start! I like the seat shape.
Title: Re: 81 CB 750C
Post by: CB MIKE on Aug 29, 2016, 09:30:51
Thanks, it still needs some work. I'm trying to keep the original seat pan just for ease of mounting. Once I get the shape I want I'm going to cut the pan and re-upholster with marine vinyl.
Title: Re: 81 CB 750C
Post by: CB MIKE on Sep 04, 2016, 11:32:44
Update:

Decided to use the old leather than re-upholster the seat. I slimmed down the seat pan and screwed the old material underneath. Got led turn signals mounted on new brackets and tail light mounted to the stock fender which I repositioned to clean it up a bit. Electrical wired up (had to get electronic blinker relay for leds) now waiting for the front end parts to arrive.

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Title: Re: 81 CB 750C
Post by: CB MIKE on Sep 16, 2016, 11:19:05
I put the drag bars, mirror, grips on, re-assembled the controls and she feels/looks great. Ill post a pic later (at work right now) but I was wondering about the rear suspension. I feel like it sits low in the rear. I know the cb750 "c" was the cruiser style. I have the manual and can replace the stock suspension however I feel like they are too short for the look I'm going for. can someone tell me how much getting longer springs will affect the bike, handling etc. even just to raise it up 1-2"?
Title: Re: 81 CB 750C
Post by: CB MIKE on Oct 08, 2016, 17:32:58
How she sits today after a nice fall ride.

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Title: Re: 81 CB 750C
Post by: NoRiders on Oct 08, 2016, 17:49:41
Hi Mike, For a C model I think the stance looks great, meaty rear tyre, shortened seat and straight bars are a 'look' in it's own right.

I have no direct experience in raising rear suspension and how it can affect steering handling, but altering the fork angle can quicken the steering or make it twitchy and potentially dangerous. However, on the basis of suck it n see, before shelling out your hard earned $$$ on longer shocks,maybe a cheap pair of shock extenders might allow you to feel the affect in reality?

Spotted these Chinese made items which might suit?
http://www.ebay.co.uk/itm/4pcs-Motorcycle-Damping-Device-Booster-Rear-Shock-Absorber-Jack-Up-Riser-Black-S-/252505476088?hash=item3aca7fcbf8:g:CMQAAOSwawpXtqRu

PS I had to read 'nice fall ride' twice before I got it haha!
Title: Re: 81 CB 750C
Post by: CB MIKE on Oct 08, 2016, 18:01:21
I appreciate your input. I agree after cleaning up the rear end it looks pretty good. After looking at other bikes I think it's more a lower font end than a raised rear. I'm thinking about just getting new rear suspension but not any longer. I've read about the steering issues with altering suspension and angles. I'm not trying to open a can of worms or add any issues just for cosmetics.

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Title: Re: 81 CB 750C
Post by: NoRiders on Oct 08, 2016, 18:18:13
I appreciate your input. I agree after cleaning up the rear end it looks pretty good. After looking at other bikes I think it's more a lower font end than a raised rear. I'm thinking about just getting new rear suspension but not any longer. I've read about the steering issues with altering suspension and angles. I'm not trying to open a can of worms or add any issues just for cosmetics.

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How about sliding the fork legs down the yokes 1" or two and see what happens? You can always correct it if it causes issues?
Title: Re: 81 CB 750C
Post by: CB MIKE on Oct 08, 2016, 18:50:21
That's a good idea I'll look into it. Thanks!

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Title: Re: 81 CB 750C
Post by: CB MIKE on Oct 29, 2016, 18:56:33
Ran into an issue, cleaned my garage and noticed the motor covered in oil. Anyone tell me why this plug would come out and where I can get a new one? It's the plug where the cam tensioner is on the front of the motor.

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Title: Re: 81 CB 750C
Post by: CB MIKE on Oct 29, 2016, 18:57:05
Ran into an issue, cleaned my garage and noticed the motor covered in oil. Anyone tell me why this plug would come out and where I can get a new one? It's the plug where the cam tensioner is on the front of the motor.

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(http://uploads.tapatalk-cdn.com/20161029/2b926c7bfbebbf41cd97b1274a120c66.jpg)

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Title: Re: 81 CB 750C
Post by: esmoojee on Oct 29, 2016, 19:21:09
Here #20 in the parts fiche http://shop.westernhonda.com/fiche_section_detail.asp?section=2569461&category=Motorcycles&make=Honda&year=1981&fveh=133013
Title: Re: 81 CB 750C
Post by: CB MIKE on Oct 29, 2016, 19:39:09
Damn that was fast, I looked at the same diagram in my manual but didn't recognize the part. I love the support within this community.  Thanks a bunch esmoojee, I'll be ordering it tonight. Any idea why it would come out?

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Title: Re: 81 CB 750C
Post by: esmoojee on Nov 02, 2016, 10:16:51
No worries, I’ve done a lot of searching for parts.  Honestly, couldn’t tell you.  Weird things happen.  Good luck CBMike!
Title: Re: 81 CB 750C
Post by: CB MIKE on Nov 05, 2016, 11:40:53
And so it begins... my winter project, complete rebuild. Today tank removed, carbs pulled, and carb disassembly has begun. I'm a noob so well see how this goes.

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Title: Re: 81 CB 750C
Post by: lostinmiself on Nov 06, 2016, 18:38:45
Why is a "C" model undesirable? I only ask since I picked up an 81 750 custom a couple weeks ago
Title: Re: 81 CB 750C
Post by: Cookie on Nov 06, 2016, 19:30:44
I don't know why anyone would outright call them "undesireable". The 'C' model outsold the 'K' and 'F' models combined, 2-1. Perhaps the huge popularity oft hem back in the day and the resultant market glut make the base and sport models appear "rare" 35 years later.
The Custom has different geometry than its siblings (actually they each have their own tweaks to the front end), set up to be more comfortable over longer trips. This unfortunately results in far less sporty handling than the Super Sport CB750F. To paraphrase Tony Foale, "everything is a compromise. The fastest, most razor sharp racing bikes  ever would be miserable on a long trip; the rider would be cramped and aching in places he didn't know he had, and his teeth would eventually be rattled out of his head. Conversely, the most comfortable touring bike would suffer greatly in a no-holds-barred road race."
The 750C is a sweet bike, but may not be the first choice for making into a performance oriented speed machine. Maybe better stock if you wanted to build a cb750 bobber or brat. The F is more geared towards the performance-minded (and not nearly as pleasant to take on trips, I have one of each). And the K could go either way, as I'd assume it's the middle-of-the-road setup.
Title: Re: 81 CB 750C
Post by: MORK on Nov 06, 2016, 20:14:15
Have fun with the carbs - they aren't nearly as hard as they initially look. There is a PDF that comes up on the first page of google search all about "CB750C carb rebuild" that you will want to follow if you haven't already.
Title: Re: 81 CB 750C
Post by: CB MIKE on Nov 06, 2016, 21:16:23
Thanks Mork, I appreciate the encouragement, I actually printed that pdf a few days ago and went by that for my disassembly. Now I'm going to soak and clean everything then put it all back together once I get my kits in the mail. Any recommendations for chemicals to clean with, I picked up a spray carb cleaner but what should I soak them in? I've read pinesol anyone tried it?  Mork I've been following your build and it's coming along nicely, you've got a sweet looking ride that's along the lines of what I'm going for.

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Title: Re: 81 CB 750C
Post by: lostinmiself on Nov 07, 2016, 00:11:04
I don't know why anyone would outright call them "undesireable". The 'C' model outsold the 'K' and 'F' models combined, 2-1. Perhaps the huge popularity oft hem back in the day and the resultant market glut make the base and sport models appear "rare" 35 years later.
The Custom has different geometry than its siblings (actually they each have their own tweaks to the front end), set up to be more comfortable over longer trips. This unfortunately results in far less sporty handling than the Super Sport CB750F. To paraphrase Tony Foale, "everything is a compromise. The fastest, most razor sharp racing bikes  ever would be miserable on a long trip; the rider would be cramped and aching in places he didn't know he had, and his teeth would eventually be rattled out of his head. Conversely, the most comfortable touring bike would suffer greatly in a no-holds-barred road race."
The 750C is a sweet bike, but may not be the first choice for making into a performance oriented speed machine. Maybe better stock if you wanted to build a cb750 bobber or brat. The F is more geared towards the performance-minded (and not nearly as pleasant to take on trips, I have one of each). And the K could go either way, as I'd assume it's the middle-of-the-road setup.

awh the "Rare" factor, im glad to hear that there isn't some flaw or something i was otherwise unaware of, ill keep it at that sorry to thread jack.

Title: Re: 81 CB 750C
Post by: J-Rod10 on Nov 07, 2016, 14:49:49
Not so much undesirable as a whole. But, undesirable in that the frame geometry of the C doesn't fit well with building a "café racer."

Not much to do with rare or not.
Title: Re: 81 CB 750C
Post by: advCo on Nov 07, 2016, 23:29:00

Thanks Mork, I appreciate the encouragement, I actually printed that pdf a few days ago and went by that for my disassembly. Now I'm going to soak and clean everything then put it all back together once I get my kits in the mail. Any recommendations for chemicals to clean with, I picked up a spray carb cleaner but what should I soak them in? I've read pinesol anyone tried it?  Mork I've been following your build and it's coming along nicely, you've got a sweet looking ride that's along the lines of what I'm going for.

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I use Pinesol on almost all my aluminum parts, usually an overnight soak, hit with a toothbrush, rinse and repeat with a shorter soak the second time around.


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Title: Re: 81 CB 750C
Post by: CB MIKE on Nov 07, 2016, 23:47:54
I use Pinesol on almost all my aluminum parts, usually an overnight soak, hit with a toothbrush, rinse and repeat with a shorter soak the second time around.


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Awesome I'll be soaking them Thursday and cleaning this weekend then!

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Title: Re: 81 CB 750C
Post by: cbrianroll on Nov 08, 2016, 00:06:17
I've never used pine sol...I've always used simple green dilluted in an ultra sonic cleaner with much success. Cook them a bit, wash with hot water, Then I spray out passages with carb spray, then blast with air to dry and blow any that didn't come off with the spray.  I also hit the vacuum piston and chamber with brasso  to polish it super smooth. Good luck!
Title: Re: 81 CB 750C
Post by: CB MIKE on Nov 13, 2016, 18:08:58
Good progress this weekend, carbs cleaned and front end disassembled. Wish my carb kits were here so I could put them back together. Hopefully next weekend.

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Title: Re: 81 CB 750C
Post by: CB MIKE on Dec 03, 2016, 17:50:39
Anyone try this cognito airbox replacement?
 https://cognitomoto.com/products/cb750-air-intake-box-sohc-and-dohc?variant=11585138177
Curious what type of tuning is required when using this. Will you run into similar issues as running pods? Also their description says it fits k models, would that also work for the c? 

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Title: Re: 81 CB 750C
Post by: coyote13 on Dec 03, 2016, 19:35:37
Anyone try this cognito airbox replacement?
 https://cognitomoto.com/products/cb750-air-intake-box-sohc-and-dohc?variant=11585138177
Curious what type of tuning is required when using this. Will you run into similar issues as running pods? Also their description says it fits k models, would that also work for the c? 

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Shoot Devin (SpeedBump on here) a PM, hear he's usually pretty quick to respond.  Likely have to jet up a bit from stock, but don't quote me on that.
Title: Re: 81 CB 750C
Post by: esmoojee on Dec 04, 2016, 13:00:39
Steel Dragon Performance makes them as well for the DOHC.  They have built in velocity stacks as well.
Title: Re: 81 CB 750C
Post by: CB MIKE on Dec 04, 2016, 13:46:28
Steel Dragon Performance makes them as well for the DOHC.  They have built in velocity stacks as well.
I've seen those ones too. I like the look of the cognito ones I'm just trying to figure out if the same issues arise as with pods on these carbs, rejetting & tuning for a not so significant performance change. I'm a noob so all the carb work is new to me and I'm not trying to get in over my head or spend that kind of  $ without knowing for sure.

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Title: Re: 81 CB 750C
Post by: CB MIKE on Dec 04, 2016, 13:51:05
Also picked up an 81 750f for $100. Mocked up the tank. Anyone know if the swing arm will bolt up easily? I'd like to swap for the disc rear. I know the master cylinder and such will need brackets.

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Title: Re: 81 CB 750C
Post by: esmoojee on Dec 04, 2016, 14:24:31
I hear you on the carb stuff.  It can be a little overwhelming. As far as the swingarm it should just drop right in.  I don't thing there should be any issues. 
Title: Re: 81 CB 750C
Post by: BigNickel on Dec 05, 2016, 15:06:53
Looking good! I'm also interested in the cognito moto filter for my 750C. My buddy gave me pod filters for free that he never used for a project he had but I hear so many horror stories. Be sure to update if you get the Cognito unit.

Cheers
Title: Re: 81 CB 750C
Post by: CB MIKE on Dec 05, 2016, 20:23:00
I'm going to hold off on the filter for now. This is the response I got from cognito "These are much like pods. They do have more internal volume but will require re-jetting. We've sold a number of these without issue."

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Title: Re: 81 CB 750C
Post by: CB MIKE on Dec 23, 2016, 17:40:36
Latest update got the f tank mounting bracket fit up and welded. She fits like a glove. Threw the light and bars on quick just to get a feel for it. The other bike is my goal for the rear end take note of my sweet paint skills. Ignore my hideous welds.

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Title: Re: 81 CB 750C
Post by: CB MIKE on Dec 27, 2016, 20:50:36
Seat hoop welded, now onto the battery box and seat pan.

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Title: Re: 81 CB 750C
Post by: BigNickel on Dec 28, 2016, 09:42:54
Looking great. I'm interested in seeing what you come up with for the battery box. I'm ready to tackle that next for my DOHC as well.
Title: Re: 81 CB 750C
Post by: CB MIKE on Dec 31, 2016, 17:54:11
Looking great. I'm interested in seeing what you come up with for the battery box. I'm ready to tackle that next for my DOHC as well.
I spent many hours brainstorming and a couple hours with cardboard and tape. Still not loving what I came up with so it may change. I'm open to suggestions.

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Title: Re: 81 CB 750C
Post by: MORK on Feb 01, 2017, 13:14:54
Any chance you wouldn't mind throwing a tape on your rear axle and letting me know the length?
Title: Re: 81 CB 750C
Post by: CB MIKE on Feb 03, 2017, 12:47:20
Any chance you wouldn't mind throwing a tape on your rear axle and letting me know the length?

Hey man sorry for the late reply. I measured it and then my furnace shit on me so I forgot to post the dimensions for you.
The overall length is 13" to the outside of the axle. Let me know if you need anything else.
Title: Re: 81 CB 750C
Post by: Rick cb650 sc on Feb 03, 2017, 14:17:06
Hi, im lurking do the ton since a while
I registered to suggest you to rotate the rear fender a bit in order to look more horizontal
A scramblish look more or less
Keep it up it's becoming beuatiful

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Title: Re: 81 CB 750C
Post by: CB MIKE on Feb 03, 2017, 14:52:46
Hi, im lurking do the ton since a while
I registered to suggest you to rotate the rear fender a bit in order to look more horizontal
A scramblish look more or less
Keep it up it's becoming beuatiful

Inviato dal mio GT-I9505 utilizzando Tapatalk

Thank you for the recommendation. I have been pretty busy lately and haven't had much time to work on the bike, just time to think about it. I have decided to go without the fender for now and it will look something like the picture attached.
Title: Re: 81 CB 750C
Post by: CB MIKE on Feb 11, 2017, 18:39:07
Doing a little work as my schedule allows. Got my fender area welded up and made some progress on the battery box then ran out of weld wire.

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Title: Re: 81 CB 750C
Post by: Cookie on Feb 11, 2017, 22:26:00
Man, I hate when that happens! Nothing worse than running out of wire mid-job.

Looking good so far though Ike; keep it up!
Title: Re: 81 CB 750C
Post by: CB MIKE on Feb 12, 2017, 11:41:15
Man, I hate when that happens! Nothing worse than running out of wire mid-job.

Looking good so far though Ike; keep it up!
The good thing was it happened when the kids were waking from a nap so I had to stop working anyways. Good news picked up more wire this morning!

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Title: Re: 81 CB 750C
Post by: CB MIKE on Feb 12, 2017, 19:22:21
I got a little more work done on the electrics box under the seat.

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Title: Re: 81 CB 750C
Post by: CB MIKE on Mar 02, 2017, 18:09:36
OK gents I need some advice. I've just about finished up on the rear end and I'm prepping to strip down and paint the frame. I threw the wheel back on to check my clearances from tire to fender area. With an F shock mounted I'm sitting at 3in of clearance in the lowest area. Trying to figure out if I will be good with that or if I need to reshape my fender to give more room. I plan on buying decent progressive shocks for front and rear but  if it needs more clearance then now would be the time to do so. I would prefer the shocks bottom out before the tire contacts the fender. Please help!

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Title: Re: 81 CB 750C
Post by: esmoojee on Mar 02, 2017, 19:22:09
You could always do cbr wheel swaps.  You’d be able to get better handling tires.  Lots of guys over at the cb1100f.net site have done them.  One of them sells a kit with the right spacers.  It’s an option.  You’d also have at least another 1” of clearance.
Title: Re: 81 CB 750C
Post by: brad black on Mar 03, 2017, 07:01:28
take the spring off the shock and collapse it.  if the tyre hits the plate, make it so it doesn't.
Title: Re: 81 CB 750C
Post by: CB MIKE on Mar 03, 2017, 10:16:42
take the spring off the shock and collapse it.  if the tyre hits the plate, make it so it doesn't.

It does hit that's why I'm trying to find out if the shocks will keep it from happening, if not then I'll have to reconsider.

You could always do cbr wheel swaps.  You’d be able to get better handling tires.  Lots of guys over at the cb1100f.net site have done them.  One of them sells a kit with the right spacers.  It’s an option.  You’d also have at least another 1” of clearance.

That is an option, I am currently just trying to run with what I have to get her road worthy and then later on look into things like that. I just don't want to add more things to the equation right now like figuring out new rear brake setup, chain alignment, spacers, etc.
Title: Re: 81 CB 750C
Post by: esmoojee on Mar 03, 2017, 12:27:56
I gotcha, riding season is fast approaching.  When you do decide to do it I would reach out to the guys on that site.  They have all the info and parts you’d need.  Good luck and I hope to see you get her out soon!
Title: Re: 81 CB 750C
Post by: brad black on Mar 03, 2017, 18:24:20
you could put a spacer around the shock shaft to limit the travel.  something with two halves that screw together.
Title: Re: 81 CB 750C
Post by: CB MIKE on Mar 04, 2017, 00:24:38
you could put a spacer around the shock shaft to limit the travel.  something with two halves that screw together.
Yeah I thought about something along those lines, that could risk damaging the hydraulic mechanism of the shock. I also considered welding some sort of stop across the top of the swingarm. How can I know the full compression of the shocks?



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Title: Re: 81 CB 750C
Post by: brad black on Mar 04, 2017, 05:57:33
your spacer will hit the top of the shock body when the bump stop hits it.  no difference to anything else, i would expect the external bump stop to limit travel before the internal anyway, and you're not going to full compression.

i wouldn't stop the swingarm, that'll stress it where you stop it as the shocks will still try to let it move.

remove the spring, that way you'll know exactly what the shock is doing. 
Title: Re: 81 CB 750C
Post by: NoRiders on Mar 04, 2017, 14:05:55
If it's the seat base that'll make tyre contact first, you could beat a hump in it, which I did, and made 20mm extra clearance at least.

No detriment to the seat foam, as I was having 50-60mm thickness.
Title: Re: 81 CB 750C
Post by: brad black on Mar 04, 2017, 19:46:54
mark where the contact is, cut the center out and weld in part of the original rear guard.  the bike you showed in your first post has the original rear guard under the tail, probably why.
Title: Re: 81 CB 750C
Post by: CB MIKE on May 30, 2017, 14:06:05
Progress has been slow due to working full time, school part time, and family obligations. I have made some progress though and been buying parts here and there. I'm hoping someone can review my proposed valve clearances. I am confident swapping shims I can improve the clearances. My concern is with intake 6 & 8. I can buy new shims but I'm not sure which side to lean toward they come in increments of .05mm. My ideal shim would be 2.68mm, so do I go with 2.65 which leaves me with .161mm clearance or do I go with 2.70mm to get .111mm clearance? Please help before I buy new shims!

The yellow are shims to be used somewhere else. Green is a good fit to get proper clearance. Red is a new shim I need to buy. All dimensions are in mm except the ones noted as inches "



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Title: Re: 81 CB 750C
Post by: Ant36 on Jun 01, 2017, 08:43:47
I would go with the 265 I am under the impression the larger clearance is better than tighter because they can be expected to tighten over time.


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Title: Re: 81 CB 750C
Post by: Cookie on Jun 01, 2017, 09:07:24
Most people I've spoken to on the subject consider .005" (0.127 mm) clearance to be ideal. 0.165mm works out to about .0065", youd be pretty close to ideal with that measurement.
Title: Re: 81 CB 750C
Post by: CB MIKE on Jun 01, 2017, 17:36:37
I appreciate it gents, I was thinking the same. I will go with the larger clearance 2.65mm it is. Thanks.

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Title: Re: 81 CB 750C
Post by: bgidman on Jun 01, 2017, 20:33:02
Mike I have the same bike..same year.  What is that seat...that exactly what I'm looking for.

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Title: Re: 81 CB 750C
Post by: Ant36 on Jun 01, 2017, 22:16:23
Speaking of the seat how did you make out with the clearance?


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Title: Re: 81 CB 750C
Post by: CB MIKE on Jun 02, 2017, 13:51:41
Mike I have the same bike..same year.  What is that seat...that exactly what I'm looking for.

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I haven't finished with a seat yet, if you're referring to the pic earlier in this feed I reshaped the original seat foam. I've since scrapped that and welded an upswept hoop, then welded sheet metal underneath as a "fender". I'm working on the cowl area now and started a custom seat pan.

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Title: Re: 81 CB 750C
Post by: CB MIKE on Jun 02, 2017, 13:55:18
Speaking of the seat how did you make out with the clearance?


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I am just going to run the f shocks because they're a bit longer and then look into a cbr wheel swap later down the road. I will have slightly more than 3" which is more than a lot of bikes I've seen run. Flawed logic I know but I'm going with it.

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Title: Re: 81 CB 750C
Post by: Ant36 on Jun 02, 2017, 17:58:49
Looking good! I'm doing something similar with an 750f.


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Title: Re: 81 CB 750C
Post by: Ant36 on Jun 02, 2017, 20:35:21
(https://uploads.tapatalk-cdn.com/20170602/7e61f9874fb0a7357f2c65410d467138.jpg)


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Title: Re: 81 CB 750C
Post by: CB MIKE on Jun 03, 2017, 14:21:45
(https://uploads.tapatalk-cdn.com/20170602/7e61f9874fb0a7357f2c65410d467138.jpg)


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Nice looks good, where you putting your battery?

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Title: Re: 81 CB 750C
Post by: Ant36 on Jun 04, 2017, 08:08:29
Lithium in the box under the seat


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Title: Re: 81 CB 750C
Post by: CB MIKE on Jun 05, 2017, 13:15:42
I didn't want to shell out the cash right now for Lithium so I made my box a little deeper and I'm sticking with the AGM.
Title: Re: 81 CB 750C
Post by: Ant36 on Jun 05, 2017, 21:34:56
I thought about it but I figured I want to do it once and be happy with it so I'll spend the extra $$.  Your box looks good though it's not really that much deeper.


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Title: Re: 81 CB 750C
Post by: CB MIKE on Jul 13, 2017, 18:39:01
Working my tail section and seat pan, still ironing out details but you get the idea of what I'm going for. Trying to carry the tank ridge and mold the led tail light into the fiberglass (if I ever get to that stage). Still brainstorming mounting ideas that hide any hardware, I'd like a clean look any recommendations are appreciated.

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Title: Re: 81 CB 750C
Post by: CB MIKE on Jul 19, 2017, 09:19:57
Fiberglass on, tank wet sanded ready for another coat. Progress is steady, she's starting to come together!(https://uploads.tapatalk-cdn.com/20170719/c5348b2d00b614932edec6deac129b80.jpg)
(https://uploads.tapatalk-cdn.com/20170719/d53cf21db783866e25656074daff5f5b.jpg)

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Title: Re: 81 CB 750C
Post by: CB MIKE on Aug 11, 2017, 22:36:33
Still pushing forward, had a hiccup mounting the tail fairing when a bolt head snapped but I persevered and got it mounted. Now sanding and cleaning everything up. I was able to salvage the old seat fabric and get it slapped on my seat pan, not perfect but works for now.

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Title: Re: 81 CB 750C
Post by: CB MIKE on Aug 13, 2017, 19:47:07
Got the rear end put together and let her get some sun while I cleaned the garage. One thing I overlooked is the small drain tank for the airbox. I have nowhere to mount it, can anyone tell me how necessary it is? Can I just run a drain hose straight off the airbox nipple? There are two nipples on the airbox one on the bottom has a hose that runs to the ground while the top one runs to this small tank that was originally on the bottom of the battery box. Please help!

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Title: Re: 81 CB 750C
Post by: CB MIKE on Aug 20, 2017, 22:12:08
Onto the electrical, hope this goes well

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Title: Re: 81 CB 750C
Post by: CrabsAndCylinders on Aug 21, 2017, 15:48:55
The blue assembly tape works well.