Welcome to the forums. Are you sure it's an '86? I don't think they started making the Fourtrax 300 until 1988. If it's an '86, it might be a Fourtrax 350. Let me know for sure if it's the 300 or 350 and I'll post instructions for timing it.
You shouldn't have to worry about rejetting it.
Most 4-wheeler problems are caused by a loose nut connecting the handlebars and the seat!!
You only need two tools in life -- WD-40 and duct tape. If it doesn't move and should, use the WD-40. If it shouldn't move and does, use the duct tape.
Last edited by Helmut; 07-20-2010 at 06:34 PM.