I'm totally rockin' the China Girl. After fiddling with the float and tightening the motor mounts a little more, I've now got her flying at 29.9 mph top speed. That's with a 24" back wheel and a 44 tooth sprocket. I'm gonna see if I can modify a 36 tooth roller chain sprocket from the hardware store to mount to my bike. That way I can cruise at higher speeds without the motor screamin'.
I've learned, and continue to learn so much from this site. I can now ride in comfort knowing things such as the fact that: the rough running sound is four stroking and it's okay, vibration is normal, and the gears are GONNA whine. The first time I rode, these were all big concerns of mine. Now they're just facts of life.
Now that she's starting to run consistently, it's time to think about my next MB project. I've got a Sears trike that's just waiting for a sturdy engine install. After I get her self-powered, I'm gonna build a corrugated plastic shell around her. It will look something like a miniature three-wheeled Dodge Caravan. Yeah, it's gonna be fun, and yes, I will take pictures. I may even start a build thread.