what i'm saying it's a 2 year old atv and it's over due to adjust the valves. chinese engines need their valves adjusted more ofter than their counterpart the japanese, also it maybe very well be it was assembled with tight valves, i've seen it before on the smaller atv's, but we don't know. besides valve adjustment is easy, quick and if it works great if it doen't you've eliminated that from the problem. set the valves at .004 intake and .006 exhaust. it's also always a good thing to do a plug check on a new atv to get a base line for future reference but most owners do not take the time or have the know how to do this.