[tcthomp66]

Thinking you might also check the air/fuel screw. I'm currently working on an issue with the air/fuel where it will either run or idle at start, but not both. If you have access to the screw, try setting it to 2-2 1/2 turns out, and see if it will idle at start. Then give it some gas and see if the engine actually revs up or bogs down.

My theory here is that you may actually have an air/fuel mixture issue. Try the petcock first (they're about $4 on Amazon), then check this. Good luck.