I have a 7-10 that I picked up about 2 months ago.It needed a new muffler in the worst way,so I put one on it & it sounded pretty nice,loud,but nice.I couldn't wait to put it in some wood,that chance came yesterday.As soon as it touched the wood the chain started slipping,so I figured it needed a clutch.When I took the clutch cover off I couldn't really find anything wrong with the clutch.A friend of mine told me that it might have a keyway,which would make sense if the keyway is sheared then the chain will slip.I proceeded to take the clutch nut off,or so I thought.I assumed,as did my friend,that it was a left handed nut.I put a breaker bar on it & heard the usual "ping"when it breaks loose.Come to find out the clutch broke due to being over-tightened.Does anyone know if Mac put right hand threads on some of the 7-10's & left handed threads on others?
Ed