I know this is an older post, I own one of these bike and 2 1970 H40 engines with the chrome chain guard. I also live 15min from Leamington where henry dyke built these, was told by Ray Michrina that he built go karts in the 60s into early 70s, go karts were 1" tubing. As is this bike. And were based off Lil Indian design, ive been told bikes were built starting in 1970 and only made a couple years, story was a go kart hurt a little girl badly and he stopped making go karts and mini bikes shortly after. My brother owned one, and ive seen 2 others complete. And all had Micro wheels and H40 Tecumsehs, (Micros were also used on go karts) anyways. Seems to be a super rare bike, Im always asked if id sell mine everytime I take it anywhere. Its a cool bike and fun to ride. Just thought this would help clarify things.