Once tried to eliminate, or at least dampen the vibration in a Harley superglide (older model). Yikes. D.A.S,T was right about the uneven firing, however it works like this:
720 degrees of crankshaft rotation are required to complete the 4 stroke cycles in a 4 stroke engine. On a Harley the...
Destroking an engine typically doesn't require cylinder block modifications. Crankshaft will have to be modified or replaced with one of a different stroke, you will have to compensate for this with connecting rods of a longer length, or pistons with a lower piston pin height.
