Howdy Uncle Salty. Nice ta meet ya.
Well y'all, I fixed the high speed cut out problem. After the chain guard was removed, I was able to lower the engine a little. I added some large curved washers between the motor and the frame to help tighten it up. I torqued it down, and now the motor is very secure. The fuel doesn't froth up anymore!!! The top speed went WAY up with no engine cutout or rough running. Then I added a tail light, and it made the motor run differently. I guess I shouldn't use a 12V bulb. I'll just unplug it during the day. I don't drive as fast in the dark anyway.
I fought with the back wheel all day. First time I fired her up this morning, the chain jumped right off. (Glad it wasn't while I was flyin' down the road.) Upon inspection, I noticed that the spokes were WAY bent. So, off with everything. I took the sprocket off, trimmed the dust cap, then spent an hour straightening and tightening spokes. It's a hard job, but I made the spokes straight enough to hold the sprocket steady again. I tightened some spokes too much, because after a bit of riding, the wheel developed a huge wobble, then it started rubbing the frame, and eventually alternating between rubbing the frame, then rubbing the tensioner. So, in a Thortons parking lot, by the light of a street lamp, I set about loosening the spokes on one side, to allow the wheel to bend the right way. I made it stop rubbing the tensioner, and it quit rubbing the frame as tightly as it had been. By the time I made it home, the wheel was almost straight. Man, messing with spoke tension is an art form if you don't have the right tools. I was using only a crescent wrench. (I usually carry two with me on rides.)
This hobby is turning out to be a regular 40 hour a week job. My friction bike is SOOOOO much smoother and is basically hastle-free. Too bad she doesn't run in the rain.