I'm putting a Husqvarna 300 engine on an old racing bicycle, by putting a sprocket on the engine and running a second chain to the pedal drive(pedals removed..). How can I put a neutral setting on the "bike" so that I can start the bike without having it lurch forward or stop me from starting it. Any other ideas are appreciated, but I am putting it onto the sprockets, and no one can change my idea!! (everyone's telling me to put a wheel on it and run it over the tire). Thanks a bunch. 
Kev
Kev