I spent the better part of a day fiddling with this thing. I replaced the gaskets/diaphrams, and adjusted my ignition timing. Things improved just a tad. Here is the symptom that I believe is causing the hickup. The high end is leaned out. When the throttle is advanced, the carb sprays a good bit of fuel out the top. Eventually it stops cutting out and settles into a good steady run, but only after about ten seconds. I can cover the carb with my hand and can really feel the fuel spitting out. It can't be being pulled out by the prop blast, since I protected it from the prop blast with my hand. I can lean out the low end to avoid this, but it is then so low that the engine will usually stop when trying to accelerate. What is the brass button inside the ventri? Does it dump fuel too. There are three jets in the body of the carb. Is my popoff pressure too low? Any help appreciated.