cb750 sohc `72 engine ticking noise

[Stenberg72]

Hi. I`ve been replacing all of the top end gaskets, the cylinders have been honed and top-sandered. Been checking the pistons and replaced new pistonrings witch correct dimention. The sound could easily be defined as problems with rockerarms or valveleak, but no.. I have lap all of the valves. I still struggle with this clicking sound that also follows rpm. I thought it could be an exhaustleak, but when I run the engine without the pipes the sound is still presence. I have also done a correct valve adjustment and the nuts doesn`t loosen up when engine starts to run. I just can`t figure out whats wrong?!?
Any similar experience or other thoughts?

Grateful for any comments.
All the best !
Torgeir Stenberg

 

[brettp]

Cam chain?

 

[Stenberg72]

Cam chain?

Thanx for responding. The tensioner seems to work fine and so do the bearings.

 

[brettp]

Thanx for responding. The tensioner seems to work fine and so do the bearings.

I'm not super knowledgeable on the SOHC bikes but I saw nobody else replied. Gave it a shot.
I'm curious what others will have to say.

 

[Floshenbarnical]

Sounds like loose valve but you said you already checked the clearances. Does the noise go away when you pull clutch

 

[Stenberg72]

Nope!

 

[Floshenbarnical]

Pull the valve covers and inspect the underside of each cap. If there are small dents or nicks then one of your valves is hitting it. I read that sometimes wear on the valve seat can occur, causing you to get a false clearing reading and giving the valve way too much clearance.

 

[Stenberg72]

Yupps! I’ve tried to start the engine without the cover but the same prob.

 

[Goldenoldy63]

Almost sounds like a rod

 

[1975 750]

im liking the cam chain,,, when the intake and exhaust valves are set to to spec ( intake .002in exhaust .003)
pg47 clymers manual these engines sound like a Singer sewing machine . check your cam sprocket teeth and if all else fails it can only the cam chain OR a bad tooth on the crankshaft sprocket …. youve done everything else
BUT pls post the culprit we are all learning from each other good luck

 

[Stenberg72]

Hi, and Thanx for sharing thoughts. Appreciate it big time! It could also be small fractures in rockerarms. Hard to say. Waiting for a new set…, eliminating causes..This summerseason has been really bad, with much rain and coldness, but next year I have to get her back on the road!!
Yeah, we all read and learn from others, so
I will post the culprit when the problem is solved! Cheers!