ORIGINAL: tkg
When you ran it on the stand you left some gas in the carb. It evaporated and left some gummie stuff behind. This kept the flapper valves from working, flapper valve no workie, no pump workie, no gas. Like the fuel in the tubing does not move.
When you went to wot and full choke the vacuum was strong enough to draw fuel past the valves and the fresh gas unstuck everything and your engine runs just like it used to.
This makes the most sense of anything so far. I kept thinking that the carb seemed like it was air bound or something. So what's the solution? Do you always run the engine dry at the end of each session? How about over a long period of down time, like during the winter?
Sounds like you've got to keep those flappers flapping for the engine to start. Is it possible to disassemble the carb and free those flappers somehow if this ever happens again?
Thanks [8D]