FRANKENHONDA II the 1982 DOHC CB 750F2 Build

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


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



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



Then I went about tapping in all the engine mount bolts



This was the top engine mount at the back



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



Then onto the front engine mounts


Rear sets and swing arm



Rear wheel, caliper and brake support



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



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



I’m 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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Ahhh you mirrored it, very cool!

My Gord, thats pretty! Nice work, man.
I really dig that seat pan

Cookie said:

My Gord, thats pretty! Nice work, man.
I really dig that seat pan

Click to expand...

The rear of it I like but the part I would sit on just doesn’t gel with me for some reason



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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Looking really good!!! You’re probably gonna have to relocate the kickstand. Hate to be the bearer of bad news but the bike looks dope!

Ok so today I thought I would try my hand at making the seat pan again...

Brace yourselves



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 didn’t form to the frame properly



Next I tried to make a template out of thin cardboard



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



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



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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esmoojee said:

Looking really good!!! You’re probably gonna have to relocate the kickstand. Hate to be the bearer of bad news but the bike looks dope!

Click to expand...

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


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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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Yea she looked good from afar but was far from good



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




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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Yea, I think they may be in the way. I had to move mine.

esmoojee said:

Yea, I think they may be in the way. I had to move mine.

Click to expand...

Have you got any photos of how and where you moved your kick stand, I’d be interested to see how those before me dealt with this issue... to be honest it hadn’t 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 didn’t even contemplate the fact it might not return to the correct place... :/

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


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Ok so the resin dried




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



I removed the seat pan and original mould ..

Unfortunately my glad wrapping wasn’t as effective as I would have liked it to be...rookie error to be fixed once fibreglassing is complete...

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.



That’s how she sits now... there are a few spots that need to be built up and smoothed out.... so now I’ll 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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Here you go. I got a tc bros and had it welded further forward close to the front engine mount.

i love this bike, its badass

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.

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

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




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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 !!

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


Seat after initial glass layup, finished off with a coat of epoxy w/featherlight additive.


After a few coats of featherlight and lots of sanding


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.

Ok so still at the hospital but had to do a run home so stuck my head in to check out my handy work

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




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



I’m 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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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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