Hello, Brand new here today, I have a problem to dump on the polaris community. I have a 1999 Sportsman 335 that has a noise in the engine at 1/2 throttle and above. It is a tinny rattle and is not present up to 1/2 throttle. Have tried to eliminate any external interferences that could cause it. Is there any history of a predictable nature that may help me correct this problem. Thank you in advance. Mel  

sound like it could be the wrist pin or possibly the rod bearing.

is it in the top end of the engine or the bottom end? could be alot of other things as well.