I searched for this and couldnt find anything that answered my question so dont chew me out. Anyways I have a 91 with the following mods. Uni Airfilter, FMF Pipe and Silencer, Lightened Flywheel, .060 over with a Wiesco piston, head mods, and port and polish. Thats about all inside the motor. Anyways i was wondering what size jet you would think I should have and how do you know what jet is in there. I bought this quad the way it is and the spark plug is looking a little black. Anyways, i think the jetting is a little off. I live in Western Pa, right now its been in the 80's. But in the winter its cold. Im just trying to give the climate becuase i think that has something to do with the jetting. Anyways id like to know your thoughts on what main jet i should be running and how to see what jet is in there at the moment. Also if anyone in the Western Pennsylvania area knows someone or can personally straighten an axle for a fair price let me know. I havent checked any machine shops around here yet so Im not sure what they are charging, but my friends uncle got his done for 30 bucks so I think it should be somewhere in that area. Thanks again to any responses.