[motiv8]

Re Post #15: When a one cyl eng reaches 30 cu. in. you'll feel the power stroke. Don't confuse that with imbalance. The power pulse can be masked w/ a heavy engine block,etc and (cw) counterweight shafts, which these engines have neither. The cw on crankshaft is an engineered compromise dealing w/ secondary imbalance. Don't alter it at random w/o proper recalculation. Also, simply changing piston assy. weight will shift the best "sweet spot rpm. You can choose the R's you use most and primary balance to that. Great fun. David