RE: gas fuel with glo plug no ignition
If you look at the pictures in the BME twin 23.6cc thread, you can see how I did my prop hub with a collar that covers part of the crankshaft, and set screws in that collar; tightening it against the crank. This gives a little added insurance that the prop hub doesn't unscrew. My Poulan 42cc is also done this way.
AV8TOR