If your spad is rather stiff you might be getting some tank foaming..... so point her up and look for that while on the ground. Make darn sure the pressure nipple is not plugged with a booger. Also, run it up to midrange on the ground and pinch the fuel line. It should speed up slightly, if not, it is running lean in the midrange for some reason still. Check everything for a possible air leak too.

Keep us posted, interesting, hope you don't have one of those GMS, 99 page threads.....

Ernie