Use a large pair of Channel lock-type pliers to hold the flywheel, while turning the screw.
If you're talking about getting the flywheel off, hold the flywheel with the aforementioned Channel locks, and hit the end of the crankshaft, or hold the engine and tap at the backside of the flywheel around the the edges of the flywheel on opposite sides, to knock it off.
I [I]AM [/I]the Driver !
Murnan Modified Motors
Rocket Science Fuels
Auto Racing, Mountain climbing, and Bull fighting are the only true sports, all the rest are just games.