My 4wheeler runs good after I push start it several times and get it warmed up, but it won't start easily when cold. Even when its warmed up the starter won't easily start it. After I get it running it will stay running and idle fine(after I adjusted the carb). Why won't it start from the starter? The starter turns the motor over fine but it won't start. Ive rebuilt the carburator. It's a 1985 Yamaha 80 and it had been sitting up for a while when I bought it. Anyone have ideas? Should I put a new starter on it?