When I was trying to figure put my lack of fuel issue, I found mine worked on TINY amounts of suction.
Mine is fit under the gas tank, with 2 nipples, gas out and (I think to a 3 way fitting one went to the carb) vacume line.
So when it would not start, I'd remove the tubing from the Vac nipple, at the pump, attach a length of tubing that fits that nipple, then like priming a hose as you would to siphoning gas, except sipping in tiny amounts of pressure, the flow would start.....to much, or to hard, the flow would stop.
So a 20" length of 1/4" tubing is in my tool kit under the seat.
And, yes I did replace that pump, all hoses, and added tiny hose clamps to all hoses, completely removed the gas tank and cleaned it.
It's still that way. Runs for while then I have to siphon it, it only takes me like 20 seconds now, but that sucks at a traffic light when it happens.

ok thanks.i'll try thaT