I've done valve clearances before, but not on a shim-under-bucket machine. I read somewhere that you should remove the CCT before doing anything. So, I removed the CCT, unbolted the cylinder head cover, and then started turning the engine to check the clearances. Suddenly the cam chain jumped over the sprockets. I didn't think much of it, and continued taking clearances (they're all tight). The chain jumped 6-7 times altogether. Now I see that (a) I shouldn't have removed the CCT so early, and (b) with the chain jumping, I changed the valve timing a bit.

Do you think the pistons could've hit the valves with 6-7 teeth out of time?

I'm turning the engine clockwise (looking at the no. 4 cylinder, from the right side)....that's right, isn't it?

What should I do next?

Thanks!!

Peter

 

If your turning it by hand you would have felt it hitting. It would have had to hit , bend the valve and continue on for you to keep turning. So I think your ok.

Obviously you need to set it back right.

 

like zaqwert said, get it back in correct time.



all you gotta do next time is not take the CCT out first. checking the valve clearances has nothing to do with cam chain tension - so leave it be until you know you need to make a change.

and you definitely would have felt it hit. i mean, you have the cam bolted down pushing down on a valve and a piston coming up and hitting it - you definitely would have noticed! hahaha


you're good. just like zaqwert said

 

Phew, OK, that's a relief!! I was turning the engine by hand and didn't feel any obstructions. However, the Honda manual says you need to insert a "stopper" thing into the CCT when removing the cams. Why is this needed? Also, I don't understand how this CCT works.....the plunger doesn't move at all. The last one I had out was spring-loaded. Thanks!!
Peter

 

The CCTs stick all the time when they get old. That's why the chain starts rattling. If your is seized then you might as well change it while its out.

 

There should be a mark on the cam gears that indicate what position they should be in when piston 1 is at TDC

 

Yes, I read thru the service manual and followed the directions. Bought a Hot Cams shim kit and changed out 14/16 shims - some clearances had reduced to only 0.05mm (0.002") !! I suspect this bike had never had the valve clearance done in its life (22,000 km). Glad I caught this before expensive valve troubles occurred. Got the cams back in and timed, rechecked all the clearances (all good), and reassembled. The bike started up instantly and runs fantastic. Thanks again for all the help!!

Peter