It is absolutely essential to almost pick up the motor by the flywheel. The end play in the crank may only about six to ten thousandths of an inch. It is not so much the weight of the hammer but the sharpness of the blow. The crank only needs to move a few thousandths of an inch to separate the flywheel. Of course the energy must be centered and directed straight down through the center the crank. Other wise you are just using the crankshaft to drive out the thrust bearing, very hard on the crank. . . 😎
