there is something wrong with the function of the accelerator pump or the path from the pump to the jet into the venturi. The pump is connected to the throttle shaft with some linkage and is actuated when opening the throttle. Normally with these old carbs the accelerator pump is a piston with a leather seal. Check to make sure the seal is in good shape. This seal should have been in the rebuild kit, normally attached to a shaft. The path to the venturi should be clear of obstructions. There should be a small ball bearing that is used as a ball check valve. This valve is maintains fuel in the path when the pump returns to idle position causing the pump cylinder to refill with fuel from the bowl.
Posted on May 19, 2012, 7:48 PM from IP address 184.108.40.206