I've had my fun in the 'Harley Riders' thread, so I thought I'd even things up a bit by showing yous all this piccy; Now given that an engine failure is a reasonable way to get dead if you muff the forced landing, someone must believe that Hardley Dangerous make a reliable engine, and the FAA must agree or it would never get the tick to fly. Hell, I might even fly it given the chance.......You don't see many (any?) planes powered by Jap motorcycle engines, although there are a few with Guzzi and BMW bike engines, and back in 1920 some brave lunatic flew on a Henderson bike motor. That is not to say there is anything wrong with say an R1 engine, its just that most modern motorcycle engines, though very high tech and capable of putting out huge horsepower, are not designed to operate continuously at high power like airplane engines. Aircraft must fly for hours on end at a steady 75 percent power, motorcycles usually operate well below that level with occasional bursts of higher revs. Where they do, like racing, they just don't last very long.