Initially it would only run if fully choked. I cleaned the tank, filter, and added a new line. Fuel flows good to the pump. Still same problem. I pulled carb and sprayed all orifices with carb cleaner from both ends. I put some new gaskets in the pump (vacuum type built into carb). The diaphram was firm but not hard so reused it. I blew into the vacuum line input to the pump and coiuld hear the diaphram working. Reassembled and installed it. Now it won't run unless constantly primed. It did shoot a lot of black colored gas out of the vent pipe from crankcase for awhile. I am stumped. Help!