Walbro pump question
 

Any one know for sure if the fuel pump portion of the carb. pumps both on negative and positive crankcase pulses?

RE: Walbro pump question
 

Built in check valves, one way pump. If it was a bi-directional pump it would pull fuel out after putting it in.

RE: Walbro pump question
 

You can use a spring in the pump and use an external pulse to the intake. AV8TOR can tell you better.

RE: Walbro pump question
 

It sucks in the fuel on one pulse and pumps it out on the other.

RE: Walbro pump question
 

Thanks TKG that is what I was looking for.

RE: Walbro pump question
 

BINGO !! This is exactly what it does. It's a very cool simple little device. Only one check valve is open at a time, and they volley back and forth duing positive and negative pulses.....that's how it does what tkg said.

See end of page 5 and beginning of page 6 for pump sequence description:
http://wind-drifter.com/technical/Wa...viceManual.pdf

RE: Walbro pump question
 

You could cut the pumping section out of a pumper carb...and use it in line to make sure fuel does not run back to tank. Capt,n;)