welcome. check my fj1100 ambulance write up projects(still on going)
hepco and Becker bags going on soon.
good luck

No luck loading pics here.
What I am looking for is images of the fuel supply line and carb breather routing. OEM set up.

Quote from: aviationfred on August 29, 2025, 03:53:41 PMSince Pat was so kind in giving me a reference. I will weigh in. As stated,I live in Kansas and ride year round. The original oil weight recommended by Yamaha was Yamalube 20w40. 40 year later, this weight is hard to find.
In every motorcycle that I own, except the Moto Morini (due to it being on warranty), I use Shell Rotella T6 15w40 year round. It is an inexpensive full synthetic that is JASO MA/MA2 certified. In the 10 years or so of using this oil, I have never experienced clutch slippage due to the oil, or any engine related issues due to oil. I hope this is helpful.

Fred

Same here Rotella t6

o-ring has to have washer between it and spring, just bad artist depiction, compared to other manual drawings where it shows washers fatter than o-rings, problem solved although any thoughts on adjusting pilot screws would be appreciated

have a replacement pilot screw assembly because the old micro o-ring was clueged. need to be sure that the o-ring goes between the spring and the tiny washer at the bottom. would have thought the washer would go between the spring and the o-ring would be on the bottom but manual seems to show different. anyone know the answer, please respond asap.

Through searching I see some people have put the FZR600 rear wheel and swingarm on their FJ but wondering if a 1988 FZR1000 would fit on a non-ABS model?

TLegg, thanks for the info! Noted on the 78 and earlier SOHC. If I can find a 76 or earlier I'll deal with the offset but good to know. Would be a shame to part it out completely, I do plan to sell much of the parts from it to convert to cafe, I'll hold it for a while and see if I can source an engine for cheap locally. I made the mistake of learning the late model GSXR USD forks fit on the CB's with the use of an adapter neck so doing a GSXR front end and wheels is stuck in my brain now!

The engine in 77 and 78 cb750f bikes are different than the earlier engines. You can install an earlier engine in your frame but the primary sprocket is 10 mm further out board than the earlier models. You could swap the sprocket carrier in your rear wheel to one from an earlier cb that would have the correct off set to match an older engine off set. they also make offset primary sprockets to fit to the older style engine but the sprocket cover needs to be changed to the one off your 78 engine  to allow room for the offset sprocket .
 the heads on the f models have larger valves and the compression ratio is higher than the cb750k. The engine was supposed to have a little more horsepower than the k models but the strongest engines in my opinion were the  K0 and K1 versions.The cheapest way to get a used motor is to find someones abandoned project bike.
 The engine in one of my 71 K1 cb's developed a bad knock a couple months ago. I found another 71 cb750 bike that a previous owner was trying to install the front forks from a late model cb750f with dual disc brakes but never finished and had no title. I paid 500 dollars for it so I can use the engine.It also had a set of hm300 exhaust pipes with silencer baffles and vintage koni rear shocks as well as a perfect rear fender, brake lights and blinkers . I pulled the engine on monday and hope to have it in my bike in the next couple weeks.

Quote from: Pat Conlon on September 02, 2025, 07:43:52 PMI remember dealing with that pesky crankcase vent.

I threw away the plastic elbow and put one of these on..

I could easily poke the threaded side into the air box and reaching into the box, capture it, slip on a washer, and thread on and tighten the nut.
I did use 2 sealing washers, one inside the box and one on the outside.

Next stop Ace hardware.  Thanks Pat

I remember dealing with that pesky crankcase vent.

I threw away the plastic elbow and put one of these on..



I could easily poke the threaded side into the air box and reaching into the box, capture it, slip on a washer, and thread on and tighten the nut.
I did use 2 sealing washers, one inside the box and one on the outside.