Annual Tuneup and Intermittent Stopping issue

[primrose]

Hello Folks,
I have had my snapper 281223BEV for 3 years now.
Last season I ran into a weird issue with my mower. It runs fine for about 15–20 minutes, then starts to stutter and shuts off. When I check, the fuel filter is dry. After letting it sit for 10 mins, the filter fills up again and it starts right up — but only runs for another 15 minutes before doing the same thing.
I’ve already:

• Drained the fuel
• Checked the tank and fuel line — no clogs
• Noticed it runs continuously if I elevate the fuel tank (put a wood block under it)

The fuel filter is mounted lower than the carb, and the fuel line is a bit long. Could this be a gravity flow issue?
Also, I pulled the spark plug — it looks dark and sooty (pic attached). Should I replace it?
Attaching pics of the tank, filter, and carb too. Appreciate any suggestions!

 

[kbowley]

Have you replaced the fuel filter? It may be restricted. The fuel line must remain lower than tanks fuel level in the tank for the full length, which in the pictures (thank you) that is not an issue... I don't believe the filter being lower than the tank is an issue if the fuel level is higher than the carburetor. Possible sticking carburetor float needle valve. Fuel cap vent. I would remove the fuel line from the carburetor and see if it flows well, and if not, replace the filter and shorten the fuel line as a second step. Let us know how you make out with the above suggestions.

 

[shurguywutt]

When I check, the fuel filter is dry.

If it was a carb issue I would suspect the fuel filter would not be dry. I am thinking it has to do with the tank vacuum building up. Try to run it with the fuel cap off and see if it runs for longer than 15 mins.

If that doesn't work try the suggestion of shortening the fuel line then replacing the filter. Disconnect from carb and check it for flow like suggested.

Also upon inspection of the photos you may have the wrong fuel filter. For a gravity fed system it should be the little red filter from Briggs. The one you have is for a system with a fuel pump I believe.

 

[Skippydiesel]

I agree with the possibility of a blocked fuel tank cap breather - follow above suggestions

Fuel filter;

• If access to compressed air, try blowing the filter out in the reverse direction of flow. Refit and see if you get a better flow from tank (into clean jar)
• Replace fuel filter - I have never heard of a filter specifically for gravity feed (sounds like a marketing gimmick)

Fuel filters can look clean, however small transparent particles , hair, etc can be blocking effective flow. This is especially possible with the pleated "paper" style - if available go fo a gauze type filter with a transparent casing, so that you can realy see what the condition is.

If all of the above fails - Fuel tank exit may be intermittently blocking - remove fuel tank. Slosh some fuel around and empty X 3. Inspect (torch) as best you can for all contaminant removal. If tank has outlet finger strainer, use compressed air to blow clean.

 

[shurguywutt]

I have never heard of a filter specifically for gravity feed (sounds like a marketing gimmick)

No marketing gimmick here. The problem is the filtration for pressurized system vs. the gravity system. Lower micron level filtration is for pressurized system (75 micron). Higher micron level filtration is for gravity fed system (150 micron). Higher the micron level (larger particle size filtered), easier the flow.

 

[ILENGINE]

Also upon inspection of the photos you may have the wrong fuel filter. For a gravity fed system it should be the little red filter from Briggs. The one you have is for a system with a fuel pump I believe.

I don't use the red filter on anything Always white or even finer. Too many logs and boulders get through the red filter causing carb issueTo the point of preventing the float valve from sealing.

No marketing gimmick here. The problem is the filtration for pressurized system vs. the gravity system. Lower micron level filtration is for pressurized system (75 micron). Higher micron level filtration is for gravity fed system (150 micron). Higher the micron level (larger particle size filtered), easier the flow.

I use to use the Briggs 40 micron on everything up to 2012 with the new tank vent systems that put a slight vacuum on the tank. When the tank gets down to about the last 2 inches it can cause issues with tank emptying. For everything with fuel pump I either use the Briggs 40 micron. 84001895 filter or the Kohler 10 micron 24 050 13-S

The white pancake filter 75 micron should not be causing flow issues on that engine.

 

[kbowley]

Simply remove the line from the carburetor and check the flow. This test ensures proper flow. Regarding filter flow and microns, one must include size in the equation.

 

[Auto Doc's]

The original factory filter is in the tank line connector portion; they did not originally have an inline filter as I recall. They were a crafty hidden small pencil tip filter design.

The other possibility is the filler cap small air vent hole is plugged with dust/dirt.

 

[ILENGINE]

The other possibility is the filler cap small air vent hole is plugged with dust/dirt.

If built after 2012 then fuel cap is non-vented style. Should have separate rollover valve tank vent system.