Bob Maddox’s stage name, Crazy Rocketman, is a misnomer. Maddox doesn’t build rockets. He builds pulse-jet engines. There’s a difference. As for the crazy part—that may be true. Maddox is the world’s ...

This whole thing is already pretty ridiculous, but some have become even wackier over the years as owners have transplanted other engines into them. We've seen one that had a 650 cc parallel-twin out ...