I just traded for a 300 4x4fw. It runs really good and has plenty of power except it smokes a little at different times and there is a clicking in the engine. I was wondering if it could be the piston rings. The smoke has a blueish tint. Also i have adjusted the valves but that didn't help any.

 

I too had a clicking sound on my 1985 Honda TRX 125, and I adjusted the valve clearance, nothing (actually, it started better) Then, I got someone to change the piston. He said the piston had overheated a few times, but now it runs perfect. Before, it would lose power, smoke, and then quit, then let it cool down, and go back home. Their is still a clicking sound, but I don't think it matters. When the guy opened up the entire engine, he said their was nothing wrong exept for the piston and rings. If I were you, just bring it to a Honda dealer and ask them, then choose whatever you feel is best, wich is probably to do nothing.