Mike, ok here we go the blue bike has motor# m17154b, the 06606 bike will be getting motor# m14741b. I also have # m17231b that includes cylinder, points housing no hardware, and a flywheel. I also have a older block no visible # i hope this helps. I do know the frame I have that has no number will be tricked out with a snowmobile engine and raked stretched front forks.