064s are noted for jerking the handle out of your hand when trying to start them. I rebuilt one for my brother in law and he is afraid his life of starting it now but won't fork out for an Elastostart. You have to pull them like you mean it. Is it running normally other once you get it started?
Thats true still have bruise marks from starting some saws. I still have an inkling that its the ignition. Could be worth getting a one of the bay see what its like.