I am trying to determine what model mechanical fuel pump is the appropriate one for this particular set up.
Currently, the one in now (no visible part #) has the standard compression oulet (looks like 5/16th) and a barbed fitting for a 5/16" hose on the input.
Originally it had a glass housed filter right before the carb but I have changed to a plastic model and relocated to before the pump. Neither filter appeared to fill more than 1/8 of their capacity yet miraculously the engine ran fine at idle and under acceleration. I tried to feed it fuel from a auxiliary gas can and it performed the same way (no restriction in the run from the tank, I guess?). Don't understand how it's getting enough fuel to keep the float bowl filled?
I thought the pump may be either the wrong type OR failing. I also checked the hard line back to the tank with compressed air. It made it to the tank just fine. All other rubber hoses are fairly new and not swollen or clogged. There are also NO leaks in the entire fuel line run.
I ordered an M6807 (Delphi MF0067)
Delphi MF0067 Mechanical Fuel Pump https://a.co/d/dPVamuy
This model pumped worse than the original and wouldn't provide enough fuel for it to run. Also, it so had a 3/8" inlet instead of a 5/16th.
The specs on it are 30gph at 2.0 psi. More volume/less pressure. I'm wondering if I should be using the M60387 which specs out at 18gph at 5.5 psi. Vice versa. (This might be the model I originally changed out?!).
The only other model I see listed is the M60330 @ 25gph at 2.0 psi (similar to the M6807).
So.....which is the correct model? What should the volume and PSI be? Is 5/16" id correct? And lastly, what's the deal with the filter not filling up and just bubbling/pulsing enough to barely fill the filer 10%?
Thanks so much for any information you can kindly give. This one is giving me more headache pain then the un-catalyzed exhaust I'm making.
