rich1 is absolutely correct. Water cooled engines which most oil is designed for run temps in the 200 deg range max. Air cooled engines run an average eng temp of 250-350 deg. Regular automotive oil will have thermal breakdown at these temps for any prolonged time. The 4 cycle ATV/motorcycle or V-twinn oil has a much higher thermal breakdown. For the best protection the Castrol full synthetic atv/cycle oil can't be beat.
|