Is it moving at all?
Perhaps you are not holding the bolt head on the other side?
If it is not moving at all perhaps you need a larger tool (say what you want). I usually will use a 1/2" drive socket, and a 2.5 - 3' breaker bar to loosen large hardware for the first time.
Harbor Freight stores also sell a cheapo electric impact driver (1/2") that will come in quite handy when working on these scoots. You will need that tool to work on the variator, and clutch.
