Just bought an 05 LTZ400 with a fresh 434 kit. They were running 0w20 in it and I didnt think that was right. I put 10w40 in it and rode it for about 2.5 hours today and all of a sudden it just died.
The quad will start, but intermittently knocks on the bottom end. Give it gas and it dies. Any ideas? Not really well versed with that kinda stuff I just know how to ride the thing.

 

If your sitting on the quad facing the handle bars is it coming from the left or right side?