Bad sound and vibration

[lovemypow]

I have a 2003 RMK and it has started to make a loud sound along with a vibration that feels like it is the belt hitting something, but the belt is fine. It is worse on the trail on downhill. It sounds a bit like when you blow a cylinder, but it is running at full power, no problem. The clutch is a bit rough when it first engages, especially if it is not at full throttle, but then the ride smooths out at higher rpm. Less sound and vibration at higher rpm going up, much louder and rougher at lower rpm going down.

Also just occured to me that this is the same sled that was having a problem with the snow flap getting caught on tread, and overheated once on the way up a cat track. Stopped and let it cool down. So, am now assuming that not enough snow was getting onto the tread to cool the system.

So, if the noise is motor damage, why would it still run at full power?

Any ideas? Thanks to all.

 

[BB454]

Check for oil in the coolant or popping the rad cap when relatively cool. That would indicate blown head o-ring.
Also check reed cage adapters and reeds. Less pressure on them when the carbs are wide open then closed.

 

[gogglefurnace]

You can't always tell if a belt has flat spots in it. Change the belt with a new one and go from there. Bad belts can make a racket.

 

[Jay]

Broken primary spring?

 

[sno*jet]

driveshaft bearing, clutch side would be my guess