Onan 5.0 has new pump but cuts out occasionally

[Roxyred]

so I just got my 72 chieftain and upon checking it out for purchase, the seller didn't have enough fuel in the aux tank to show me the onan worked. So he put a longer fuel line to the fuel pump into a gas can for demonstration purposes. Worked great.


Upon setting it up for actual use off of the aux tank, I decided it'd be nice to leave the long line in case of running the aux tank too low on fuel to run the onan. It worked GREAT with the the long line for 12 hours of use (4/4/4) then was acting like the new fuel pump was either fuel starved or hot and cutting out. Upon moving the line around, it seems the line needs to be level with the aux tank fuel line and the pump or the pump has issues.


Anyone else have a long fuel line cause fuel starving? It's a basic piston type pump, but I don't know the output, I didn't install it.


Thanks!
Roxy

[Rickf1985]

these pumps are "pusher" pumps and are designed to be installed close to the tank in normal operation. In a scenario like the generator, the generator is level with or even a little lower than the gas level in the tank so they can get away with the remote mounting. The pump will not pull gas up from very far below the level of the pump though. And the larger the line the less distance you can pull due to the weight of the liquid in the line. You should have a 1/4" line on there. If you set the gas can on a step so that it is level with the generator does it continue to run then? You may also have a clogged fuel filter and the combination of the lift and the resistance in the filter is overloading the pump. Also check to be sure you are getting a full 12 volts to the pump.

[Roxyred]

Thanks! I am pretty sure it is the length of the fuel line, I repositioned it and now it runs just fine again. I'm going to put a new shorter piece in this week. Thanks for the help!