Originally Posted by
earlwb
Did you make sure that the passage that lets the crankcase pulses get to the carb pump are open and clear?
There is a passage to allow for the crankcase pulses to reach the pump diaphragm so it will move back and forth and pump. If that passage is blocked (eg putting the carb on the other way) then it won't pump. Some engines used a fitting and a short length of tubing to route the pulses to the engine too.
After looking at the picture on their website this engine DOES have this tubing. If it is not connected on your engine it will not work. A picture of your engine would help.
One sure way to tell if your flaps are flapping is to install new diaphrams. This will achieve two things. Either it will fix your problem or you will eliminate it as a problem.