Topic: Bought my first CB750 - Advice Needed

[BSAKat]

Are F/Supersport cylinders different than regular old K-model cylinders? Specifically for a '76 Supersport engine.

The 76 SS/F and the K models use the same cylinders.

Awesome, thanks.

Update?
How’s the project going?

Haven't really started yet. I had a long slog with an XS650, then an XS1100 fell in my lap, and now I'm putting together an XS7502D for my buddy who's currently between bikes. He's trading me work on my BSA project for work on the 750 since I'm the Yamaha Toucher. The CB750 is up next.

The plan, such as it is, is to rebuild the engine from the '76 and put it in the '75 frame. The '75's engine is a disaster, and cylinder 1 is rusted solid. The cylinders from the '76's engine are hashed, too, so that's why I need a new set. The '76 engine will get a thorough inspection and a full top-end rebuild. Hopefully the bottom end is solid, since it sat in a garage under some towels for 30 years with oil in it.

Once I get the engine swapped, I'll replace all the rubber on the blue '75, spruce up the electrics, rebuild the brakes, reinstall the headlight bracket, and do what I absolutely need to get it on the road.

[PeWe]

Sleeves can be replaced. If cylinder look good on its outside, well worth to find good sleeves from an another cylinder with damaged fins beyond repair that has not rusted inside.

Cheap Cruzinimage pistons, +0.5 or +1.0mm for deeper rust to make it to run well. Head needs most likely new guides and valves, at least EX side.

[Don R]

I'm a big fan of the 75/76 F's, I only sold mine to help pay for a sandcast. I did the double disc brake and loved it.

[BSAKat]

I'm a big fan of the 75/76 F's, I only sold mine to help pay for a sandcast. I did the double disc brake and loved it.

This is my first experience with 750s in general—I've rescued/restored/ridden CB200s, CB450s, and CB500 fours—so I'm pretty excited to dig into it. My biggest concern is that two-piston rear caliper, which seems to be made of unobtanium along with all its parts. Mine is junk, and I see I'm gonna have a hard time replacing it.

[Don R]

 I have one too that I have not really looked into yet. Recently there was mention of newer calipers swapping onto that bike. We need to check that out. I'm refurbishing fronts today.

[bryanj]

You can get pattern pistons and seals forthe rear caliper, the only difficult part to find is the little square section O ring between the halves, but unless you mangle it that can be reused