Hi, everybody!

I bought a 2001 man.500 cat in July...it has a knocking noise coming out of the right side of the engine case...especially at low rpm's with a little load on the motor...go's away at higher rpm's...sounds kinda like the hammers in a impact wrench...also can do in neutral with or without the clutch engaged at rpm just above an idle. Bearing? basket? ??
It has been doing this since new, and now has a little over 450 miles on it so far with no break-downs(only had to shim the front springs a little). Anyway,TWO dealers(including the one I bought it from)tell me the noise is normal,but they do not know exactly what causes it.
If it is indeed "normal" then is there an explanation? or fix?
Thank's for the help!

 

Sounds like you are talking about the compression release. On automatic compression release models they have a tendecy to make that noise when idleing. And the faster your motor turns (it's mounted on the cam) the less you notice it because it is happening so fast.

Have you had your valves checked yet?? If not, I would recomend doing so.

 

My 01 500 has been doing it since new, 7mo old 1300 mi, no motor problems ...Bill

 

Valves A-OK...the noise is coming from the lower right side engine case area at center and is loudest at crankshaft level. It is not a tick, but a knock. Could it be the clutch rattling?? I am not very familiar with this engine and was just curious to see if many other people were experiencing this noise, and what it might be. Thanks for the reply's!

 

My 2000 400 makes the same noise, it is the clutch. It is considered normal. I have listened to new bikes at my dealer and some used, they all do it to a greater or lesser degree. I called AC and as well spoke to my dealer about the noise and both say don,t worry about. In fact my dealer has yet to sell a replacement clutch for an AC bike and he has been with AC [ATV] since day one. The noise it much more pronounced at very low RPM and when the engine is cold. Boner might be able to shed some light on how many AC clutches are being sold.

Cheers Jim

 

Thank's Jim !
I suspected as such...I too have heard it on other bikes also, but was not sure as to why.
So far so good no other problems at all...good bike.

 

I've never heard of an Arctic Cat wearing out a clutch, but I can check with another dealership that has been open a long while that sells to MANY farmers (aka LOTS OF MILES ON BIKES) AND see if they have ever heard of it.

 

Boner is right,I have the same problem. I went back to the dealer with the same concern and was told it was the compression release and it was ok even though it sounds bad.

 

Boise, if you went to All Terrain Sports and got that info you can be assured that it is correct. Jerry the Mechanic and Don the owner are both pretty sharp. I would trust their answer. I have an Auto that I bought from them and they have always been fair, honest and way above board on everything.