CBR600F4 timing chain issue

[HarryJenkins]

Hii..

A couple months ago I picked up a '99 CBR600F4 that needed a little work. Wasn't really looking for another bike but the price was good enough that I couldn't pass it up. I just rebuilt the carbs and did a valve adjustment but I'm having an issue with the timing chain when I attempt to reinstall the cams. Everything seems to be in proper alignment. The notch on the crankshaft, the mark on the intake sprocket, and the mark on the exhaust sprocket all line up perfectly. I made sure to leave the only slack in the timing chain between the intake sprocket and the crankshaft sprocket and proceeded to reinstall the tensioner. When I turn the crankshaft manually everything turns easily and all markings stay in alignment after a full rotation. The problem is that at certain points throughout the rotation the chain jumps and seems like it's about to skip teeth on the cam sprockets. It doesn't actually change teeth and everything stays in alignment, but I can't imagine it would be good for this to be happening at 1300rpms. Sorry if I didn't describe the issue very well. I've tried to post a video but the attachment tool gives me an error even when using allowed formats. I posted a video on Youtube but since my account in this forum is new I can't link to it. Anyone have any ideas how I can correct this?

Please help..!

I didn't find the right solution from the Internet.

References:-
http://www.motorcycleforum.com/59-motorcycle-repair/223041-cbr600f4-timing-chain-issue.html
case study examples

Thanks!

 

[dirtdigger]

It may be a weak timing chain tensioner...they go bad often. If it is not holding tension the chain may jerk or snap as the camshaft roles over a cam lobe and the valve spring pressure tries to turn the cam....if there is any slack in the chain it will snap or jump. If it had a rattle when idling before you did the work then it for sure has a bad tensioner.