Engine Air Filter, Engine Oil And Filter Use regular unleaded gasoline with an octane rating of 87 or Attach the oil drain hose, furnished with the unit, to the oil higher. Be cautious not to damage the shaft threads on the engine. If yes, that means the magnetic function of the clutch is properly working. Find the grounding point for the clutch and clean that area. On older machines there are reasons for a clutch to not slide off with relative ease.