I have a 1990 XT600E with about 33K miles on it. It runs like a champ and pulls hard, so far it's been a great commuter from the east bay to San Francisco. I know these bikes are rather noisy but mine makes some odd sounds (more recently).

When I'm around 3,500-4,000rpm and add throttle I can hear what sounds like a gentle chittering from the valves that turns into more of a valve clatter (not overly loud though) as the RPM's raise. It sounds like tappet noise but it really only does it in 3-5th gear on the freeway when the engine is under more load. The valve train is also quite loud if I accelerate hard from 75-95mph (especially if it's uphill and in 5th). It doesn't sound like it's coming from the bottom end and at idle it's nice and quiet.

Is it possibly a bad cam chain? There are about 9 notches left on the tensioner. Also, if it was loose I would think there would be some aluminum from the cam chain tunnel but the oil is spotless aside from being dirty.

I set the valves last month with the engine at TDC on the compression stroke but I'll be checking them again tonight. Other then the loud valve train the bike has been great, it smokes a lot on startup now but I'm pretty sure the oil is overfilled and the check valve is probably bad (no visible oil in the tank after sitting a few hours).


I've lurked here for a long time reading up on stuff, this a great site for XT info .