KC, I'm giving up on making a custom jackshaft. Since I had my stroke a month ago, I just don't have either the patience or the endurance for fabrication like I did. I don't even like to weld now, the smoke irritates me. Am considering your advice on using a SBP unit. What has been your experience with 4 stroke engines? Am getting my rebuilt wheel with Shimano hub from my bike shop tomorrow and I'm anxious to get this thing finished so I can ride it again.