B7800 - Fuel bowl running out of fuel

[Sniggle]

So my temperamental B7800 is doing its thing. I have had it die on me a few times, and this morning I got it running, ran well for a couple passes with the belly mower, and then puttered and died. I got off right away and saw, as suspected, the fuel bowl was 1/2 empty (note the fuel tank is over half full, new fuel filter). I watched as it very slowly filled back up, then it started again but it quickly got ahead of the fuel bowl and it died. Tried loosening the cap on the fuel tank, same result.

So I need to figure out why fuel is not keeping the fuel bowl full.

I figure it could be:
- obstruction in fuel tank or line to the filter
- Fuel pump failing to pull as designed.
- Something else?

Any thoughts/recommendations would be greatly appreciated!

 

[Roadworthy]

Disconnect the fuel line as close to the tank as you can. Have a container handy. See how fast fuel flows from the tank into your container and how long it will sustain the flow. That will tell if you have a tank output blockage. Of course your new fuel filter could be defective as well.

 

[Sniggle]

I will do that this evening when it is a bit cooler. The more I think about it the more it makes sense that the issues is between the filter and the fuel tank, because the fuel pump has no problem driving the engine when the fuel bowl is full.

 

[Sniggle]

Yesterday I removed the fuel filter and looked at it. It was missing some of the top ridge on one side, so maybe that was enough to not fully open the flow from the fuel tank? I pushed the spring-loaded valve on the fuel filter assembly, and fuel came out with good flow. I also removed the fuel line from the filter housing briefly, and got good flow. I did have another fuel filter, but on inspection it was damaged (torn) so I ordered a few more to arrive Saturday.

So it looks like it may have been the fuel filter top edge damage not fully activating the flow valve, or maybe when I hand activated the fuel filter assembly valve something dislodged. Time will tell, I guess. Hopefully it is this easy

 

[LHoyer]

Check tank vent. Usually integral with cap.