Motorcycle Repair: 1989 CBR 600, cbr 600 1989, chain tensioners

Question
1989 CBR 600
27,400 mi.
My 600 makes a rattle sound.  It rattles at low RPM's.  It sounds like marbles rattling or maybe a loose chain inside the engine.  After RPM's go so high it stops.  Also it seems to go away when the engine has been running for awhile.  I've checked the CAM chain, but tight as can be.  This has been going on for a few years now.
any ideas?
Thanks,
Chris

Answer
Hi Chris,

27,400 is many miles for a sport bike, and a few of those are aggressively ridden miles, I'm sure. :)

Cam timing chains will make noise below the head where chain tensioners are located.

Other possiblities are: loose vlave clearances and general wear of engine components.

Perform a cylinder compression test and leak-down test to know the condition of the engine. Check service manual for valve clearance and other basic maintenance procedures.

Respectfully,
Mark Shviely