I dont think a whizzer crank will work. I'm good friends with jbcruisin,and he has quite a few original whizzers. The whizzer engine crankcase was designed to fit between a bicycle's stock pedals, and I've seen his collection, none of his bikes have offset pedal cranks. And although a 4 stroke is also a china motor, its wider than a 2 stroke and stock pedals may not clear it. Buck, I recently built a 98cc cruiser (described in my signature), and I actually had an offset one piece crank that was still not wide enough. I went to Lowe's ( Home Depot carries them as well) and bought a propylene ( NOT propane, propylene, comes in a yellow cylinder) torch with the nozzle included for $50. I put my crank in a vise (with some help from a friend) and we heated the arms till they got red-hot, then put a seatpost (any pipe will work, but a spare seatpost was handy) over the arms and bent them, out in one spot on the arm, back in at another, so they would still line up straight. Once you get them red-hot, they bend like butter. Let them cool at room temperature so they don't lose their temper or become brittle, and you're golden.
