1980 Honda CB750F Cafe build

[flatpick13]

Hey, a little late into my build but figured I'd post pictures to date for everyone's viewing pleasure and maybe get some feedback that helps me along the way (btw, thanks to everyone who's helped thus far!).

Quick summary: purchased two 1980 Honda CB750Fs back in October, both were in pretty rough shape and had been sitting in the elements for 20+ years. I plan to cafe one of these, and the other will get rebuilt for my wife to a design of her preference (this is TBD still, I think she's leaning towards a brat build or resto...).



List of planned work for current build:

- Rebuild top/bottom engine (new bearings, new seals, inspect/replace cams, valves, shims, crank, gears)
- Paint engine (satin black)
- rebuild/replace carbs (will use air pods)
- new exhaust (4-into-1 or 4-into-2-into-1)
- rebuild and lower front forks
- scrub and paint wheels
- front fender chop
- tank, seat, and fender paint job (black with white stripes)
- rebuild brakes
- chop and hoop frame
- Powder coat frame
- fabricate fiberglass cafe seat (w/ integrated brake/turn light)
- m-unit install (new wiring harness, new battery (either lithium with a new regulator, or AGM))
- custom electronics tray and battery bracket
- new speedo/tach (trying to fabricate a sensor to still use the stock analog speedo cable off the front axle)
- Clip-ons w/ bar end mirrors
- New headlight w/ integrated turn-signals
- new high-dB horn mounted under the tank behind coils
- New hand controls (buttons and levers)
- Clean/re-grease all bearings

Pretty sure I forgot a few things in there, but I think you get the gist. Pics and list of work-to-date in next post.

 

[flatpick13]

So, work completed to date with a few pictures:

Bike stripped down for cleaning




Frame cleaned, chopped, and welded (still pending powder coat, waiting until I finish up the seat and a few other things so I don't mess up the new finish)


Engine disassembled, inspected, cleaned, painted, and rebuilt:


I've also started on a custom m-Unit wiring diagram (will share once complete and tested). Just had to crate everything up to move, but will knock out the seat fab, wheel cleanup and paint, and fork rebuild/lower in the next couple weeks once I'm unpacked. Carbs are also coming up next, sent a post for some advice on that one, but I'm not relishing the idea of making the CV carbs work with pods and aftermarket exhaust....

 

[amc49]

Best thing I could say would be 75-115 on pod jetting and the exhaust must WORK rather than just being cosmetic and the engine must be well sealed too to draw correctly on the CVs with pods. CVs work best slightly lean, any rich and they will drop slides to open slower and lower.

Adjust valves to .005" instead of the book .003", the engine will love you for it. Use .004"-.006" as the range, they WILL burn valves at .002" even though book says it's OK. Essentially you toss .002" of any valve clearance you get, it is not real at engine running, it becomes zero.

 

[AlpineJumper]

So, work completed to date with a few pictures:

Bike stripped down for cleaning
View attachment 9657
View attachment 9658
View attachment 9656

Frame cleaned, chopped, and welded (still pending powder coat, waiting until I finish up the seat and a few other things so I don't mess up the new finish)
View attachment 9659

Engine disassembled, inspected, cleaned, painted, and rebuilt:
View attachment 9660View attachment 9661View attachment 9662View attachment 9663View attachment 9664View attachment 9665View attachment 9666View attachment 9667

I've also started on a custom m-Unit wiring diagram (will share once complete and tested). Just had to crate everything up to move, but will knock out the seat fab, wheel cleanup and paint, and fork rebuild/lower in the next couple weeks once I'm unpacked. Carbs are also coming up next, sent a post for some advice on that one, but I'm not relishing the idea of making the CV carbs work with pods and aftermarket exhaust....

Hey, that engine looks awesome. Great job. You ever get together a DIY m-Unit? I'm trying to do the same, as they're super back ordered. Kinda at my electrical ability limits at the moment. Would love some help.

 

[MrsZDaquri]

My husband is really wanting to café our '80 CB750C. The top project on the list is finding a seat that has the light integrated into it. I said we should figure out how to make one, as there really isn't anything after market that's checking all the boxes. When I saw that on your to-do list, I had to pop in... how's that coming along for you? Is this something you've dabbled in before or kinda figuring it out as you go? Give the list of work you're doing I'm assuming it's not your first rodeo... it's ours; any advice? Thanks!