I am restoring a Duster mx and have a couple questions. I believe they came with a 3hp Tecumseh engine? I have seen a thread that Leathernun666 posted and he had a 5.5 hp engine (don't know brand) in a Duster. Would like to know what engines are compatable without too much modification. Gonna need pretty much everything for the bike, wheels, tires, brakes, shocks, sprokets, all shot. I've seen springs being sold for forks, are they 5.5"? Any help is appreciated.