Spinner:

You're right, It was Iffy Les, first post in this thread, that had the air getting in at the pump. A pin hole in the diaphragm will allow some of the crankcase pressure gases to get on the fuel side, giving the air in the delivered fuel. He is the one who needs to return the pump.

I really don't know any more to say on yours, it just sounds like you're not getting sufficient fuel delivery, but I've never had that problem on an engine up to 1.50cid.

Maybe you should return yours and ask that it be tested for volume of delivery.

Bill.