Topic: Cb500 gearbox / clutch problem, probally

[Number8]

Heya , new to this site , shame realy whish id found this site a month or so ago save me buggering about with a multimeter for weeks!
First off a quick overview ,
I bought a 72 CB500k1 from a friend about 6months ago and have finally got round to getting it running , it had been at the back of his shed for about 20years! Not the intresting bit it apperes to have had the full yoshi catalouge thrown at it and some serious head work to as none of it measures up to standard and ive loads of recipts from a tuning place in london ( im the uk btw)
I got it running about 3days ago ..

but the bad bit is, theres a REAL nasty rumble coming from the clutch/gearbox
no im no expert at these sohc hondas so i need  advice

right the simptons
-Heavy clutch (cable is lubed and mech is fine)
- Rumbling nose is like id imigane a bearing would if ya took out half the balls! coming from the clutch
- Noise goes away when reved
- Also go away when u pull the clutch in but it slows down and stops after about 10 secs
- occasionally jumps into gear while pushing it about in neutral ,
- the neutral light dont werk , no big prob that is tho
- the gear #$%*s is realy heavy and erratic

Thats what i dont get , why is the clutch heavy , but the sound apperes to be come from the gearbox (noise slows down when u pull the clutch in) unless its shares a bearing ..... im lost ...  ive only ever worked on modern motors and never split the crank cases

also ive got a 550 motor in the garage , will the gearbox/ clutch outa that fit in the 500 ....

cheers
Oliver

[number13]

Just found a Yoshi 500 sitting in a friend's yard? Man, I need some friends like that.

The way you describe the clutch noise it may be the clutch rod lifter mechanism, located inside the
left hand case. Take it apart and look for cracks in the sleeve. Also look for signs of the lifter
clashing with the chain/sprocket, especially if the bike has been fitted with a new O-ring chain

Erratic shifting and gear jumping may be the shifer detent ball and spring, located on top of the engine case
directly below the number 3 carb. It looks like a hex bolt.
The clutch on my 73 is always a headache, I have spent a lot of time optimizing it and have finally
gotten it to work well. Keep at it, it just takes time and intuition.

[Number8]

cheers man ,

it was his dads bike and he always said he was gonna get back on the road but he passed away last year and he finally got round to sorting ou his stuff and binning/selling stuff

oh well ... time to start ripping into the motor ,

[bryanj]

If the clutch cable is original and you lubed it with oil thats why its heavy as the originals were nylon lined and any lube causes it to swell and bind. Try a new cable. The noise is a worry, could be just carb balance which is fairly critical BUT the LAST in the service schedule It could also be rust in a gearbox bearing track all of which are still available from Dave Silver. If you want you can ring me on 07795162623 any evening Sunday to Thursday as I work nights.