there's a shoe clutch that engages by centrical force, bathed in oil that aids in the start from a full stop. There is also a plate type clutch that disengages (same as pulling in the clutch on a manual motorcycle transmission) when the shift lever is pulled up and engages again when the shift lever is let back down. If you hold the shift lever up and rev the motor up above the engagement speed of the shoe clutch, when you let the lever back down, it is putting all the wear on the plate clutch, just like"popping" the clutch on a motorcycle to break the rr wheel loose.:yeahbaby01:......... Both clutches are bathed in oil so if your oil smells "burnt", it's a sign of failed and/or failing clutches. This is also a good reason to change engine oil frequently because all those worn clutch particles are also floating around in the engine oil.