"Morgans" wrote in message
...
Most have the gearbox made as one with the lower crankcase. You can't get
the weight off of the engine, and the gears in the bike tranny are not tough
enough to run a prop, so you have to live with the weight and figure out a
way to get the power out of the case without using the gearbox. Big
problem.

Of course, that is not so with Harley & clone V-twins and at least some BMW
engines (Yes, I know. They are 4-stroke and this thread is about 2-stroke
engines)

Vaughn