what fuel do you use(color) - id start by always draining the fuel out of the tank if you store it for a period of time. a week should be ok but no more than that. its hard to tell ? put a new plug in and before you do- leave it out ond crank it over to blow the excess fuel out. then go back to the factory settings and go from there. also try to warm the motor up w/ a heat gun or hair dryier. it does help...200deg.