KZ750 camshaft problem

Hi,

I just installed back the camshaft. I did everything according to the manual. The piston is at TDC, the exhaust and inlet camshaft are at the right pins. The tensioner was put back before running the engine. Valve clearances are good.

However, the cam chain didn't run smoothly. It was kind of rattling. I filmed a short clip to demonstrate the symptom.



Any suggestion is welcome. Thank you.

Does it make the same noise when the valve cover is installed? I ask because there is a cam chain guide in the valve cover, and it's possible that the guide provides some tension on the chain. Ed

It makes the same noise when i put the cover back. And because I didn't have the pick-up coil cover on, I can see that the crankshaft bolt have like a rapid stop and did't have a smooth revolution. Thank you.

Starter gears out of alignment? Does it turn over smoothly by hand?

Before you put the cam cover on you have to loosen the cam chain tensioner!!!
If not you will over tension the cam chain and and all other components.
After a cam install never turn the the engine with the starter motor.
Remove the spark plugs and turn the engine by hand to get save not to bent a valve if the timing is out of spec.

+1
Loosen the tensioner if it's a manual one. Remove it if it's the original tensioner. Put the cam cover on. As Ed said there should be a rubber block in the centre of the cover which depresses the cam chain between the sprockets. Remove the timing cover and set the crank to the T 1-4 mark. Install the cam chain tensioner and set it. All should be well.

What you are seeing is exactly what would be expected with cover off and tensioner in place

NEVER RUN IT WITH THE COVER OFF.

Now before you do put the cover on recheck the cam timing.

OOOOhhhh. Hearing the engine cranking scares me. I hope the timing chain is not skipping teeth on the crankshaft sprocket. If that is the case, then the timing would be so far off that valves may have already been bent by hitting pistons.
Hope I am totally wrong. Re-check the timing again to start with. Then loosen the chain tensioner; install the valve cover; re-install the tensioner and try again. Good luck.

biwithse7en wrote: It makes the same noise when i put the cover back. And because I didn't have the pick-up coil cover on, I can see that the crankshaft bolt have like a rapid stop and did't have a smooth revolution. Thank you.

By the way you describe that the crank was suddenly stopping and wasn't smoothy rotating, that to me means that your started clutch is slipping. The sound you hear is the starter clutch rollers chattering as they try to lock up and turn the motor.
Since the clutch rollers loose grip the engine stops turning over creating that stuttering rotation of the cams.
Turning the engine by hand will let you know if the cam chain is indeed slipping off the crankshaft. (very very unlikely)
So if turning by hand you can't replicate the slipping, your starter clutch is to blame.