Originally Posted by cschade
I'm using a 12 tooth clutch off the engine to a jackshaft in. The jackshaft out is the standard bike gears (the large three sprockets in the front)
running to the usual rear freewheel gears.
That won't work, you need way more gear reduction than that and how did you plan to keep you feet from getting beat to dead by the pedals when the motor turned the pedals?
Check out SickBikeParts 4-stroke jackshaft kit.
And that is with a gear reduction transfer case, you are planning to run direct off the engine so you need even more reduction.