I was thinking about it, and I came up with 2 simple ideas. The first, is adding a lock to the clutch handle. You can't pull it in without unlocking it. It would be one of those locks that just turn 90 degrees, like a locker works. The second is a electronic type lock that gets wired up between the CDI and the engine, at least that way the engine is useless without a key (unless they reqire it, which they wouldn't unless they took it home). Thought?