hi i'm new here. I have installed a K&N airfilter on my atv and i wanna remove airbox lid. i dont ride in mud and water that much. should i re-jett it and what size jet

 

You will need to rejet, because its gonna be much leaner than it was.
You may need a size up on pilot jet, but for sure at least 1/2 turn richer on the mixture screw. Then id start with a main jet 3 sizes bigger than stock ( number is stamped on the jet), and go from there.
Heres a good article on jetting to help guide you thru the symptoms of lean and rich.
Jetting article

 

thank's for the answer[img]i/expressions/face-icon-small-smile.gif[/img]