Does flywheel need to be balanced

[nkaminar]

If the balancer is using centers at the ends of the crankshaft. The crankshaft has conical holes drilled in each end that was used to grind the bearings and is used to balance the crank. If the balancer presses in too hard on the ends it could possibly deform the crank at the flanges for the rod journals. The force is off center at those flanges.

Beware that sometimes the centers, the conical holes, are not on center and the journals at the ends should be used.