• Enter the March CB750 Supply gift certificate giveaway! It's easy... Click here, post something, and you're entered into the drawing!

first cb

chopper750

CB750 Enthusiast
Messages
83
Reaction score
0
Points
6
Location
arizona
so im planning on buying myself a cb750 theres two i am looking at ones a 74 thee other is a 78 which is better ? my question is what should i look at in the motor before buying besides compression.. how do i check the cam chain adjuster im guessing that a big sign of wear and if i should how do i do it ?
 
any thoughts would be great guys.. oh and a little about my self ive never owned a honda always yamahas but i heard these cbs are good bikes and i would love to build a bobber im pretty good with engine stuff like carbs and checking for problems and correcting them just gonna need a little help with welding and what not anyways thanks for yhour time
 
I would go with the 74. The 77,78 era are a good performing motor but these are the goofy years that honda was changing some things around with the cylinders and heads and can be confusing and harder to find the right parts. If you can get the 78 for really cheap go for it because it would still be worth it, but my choice would be the 74 motor. How many miles are on the bikes? Check see if oil is really dirty like it has been neglected. Look for major oil leaks because if you have to fix a head or base gasket then the motor has to come out of the frame. Timing chain tensioner cant really be inspected but is a maintenance item that is part of a good tune up. You will have to go over the tuneup when you get a bike, plugs, points/condencer, set timing/dwell, adjust timing chain, adjust valves, oil change, sync carbs, etc.
 
both bikes have about 25k and what are good compression numbers for these bikes.. and to check comp you gotta have throttle open and then kick til the gauge stops ?
 
Honda spec for compression is 170psi, if they have been sitting for a while you can expect them to be lower until you get it running for a while. Use only the electric start to get accurate compression readings. With the kickstart you will get inconsistent and lower compression because of the slower engine speed as compared to the electric start. And yes holed the throttle wide open. Take all 4 plugs out before doing the test. Rule of thumb is turn each cylinder over 5 compression strokes and read the gauge and do same on each cylinder. First compression stroke should have the larges increase in compression and each of the 4 successive compression strokes should add more to the first. Just be sure to do the same on all 4 cylinders to get an accurate comparable representation between all 4.
 
well neither one runs but ill bring a battery nd see if i can get it to turn over if not ill just check with the kickstarter if its a little low i know why
 
Back
Top