hircflyer,
Had a similar problem with mine. Ran fine on the bench, wouldnt start in the plane. After fueling, I raise the tail of my plane so the fuse is level. Choke, ignition off, spin the prop with the starter to prime, lower the tail, ignition on, hit it with the start and it starts right up. Dont understand it, but it works. My tank is right inline with the carb. Its also the stock carb off a ryobi weedeater. Was rebuilt when I modified it.
Edwin