Forget about 3 pumps - mine takes 15 at least. If it defiintely isn't priming at all, there should be a gasket between the air filter backing plate (with the built-in primer) and the carb body. This has a channel cut in it (which makes it almost impossible to make a gasket, you'll have to get the correct one). If the gasket is damaged or missing, it'll never prime.
phil_saunders@bigfoot.com
Phil Saunders, June 2008