It all started with my uncle Bob. Everyone has an uncle Bob right? Mine is a fellow bike dork. On a trip to his house for Easter I believe. Bob tells me of a freeby score that he got. A 1975 Yamaha RD-350. With an engine frozen up, and other projects on the burner, he gave it to me.
The Yamaha's were 350cc parallel twin 2-strokes from the days when 2-strokes were still street legal in the US. This mighty engine produced 29kW (39HP for you US dweebs) at about 7500rpm. It has compression of about 6.6:1 and a bore and stroke of 64.0mm x 54.0mm. Compared to todays modern sportbikes that is fairly petty power. But this is 2-stroke power. 2-stroke power is different to ride then 4-stroke. Since the engine is delivering a power stroke every revolution of the piston, there is less gap in the power. That power coupled with a 6-speed tranny made for a bike that will wheelie through nearly all the gears with even my 200lbs butt on it.
So here it is. Check out the link here. This project is going to be a lot of fun. I can't wait for 2-stroke goodness.
Sometime in early 2006 I scored a couple of engines from someone off of Craigslist. I walked a way with a nicely rebuildable 350 like what came out of the bike originally as well as a 400 from the later RD-400. The 400 shares the same motor mounts and will basically bolt right into the frame for an added boost in power.