Ghost in the tractor... (Engine suddenly quits with motion)

[ericm979]

Re-reading the original post I'm thinking more of an electrical fault, like a wire that's broken or a connection that is loose. When the fuel runs low the engine sputters as it goes lean, rather than cutting off like it was switched off as the OP describes.

A lot of things could be the problem but one I don't think has been mentioned is the seat safety switch and it's wiring.

 

[nybirdman]

Replace the fuel pump;cheap and easy.

 

[macindude]

Well... Before I pulled the carb apart I decided to replace the fuel filter and check for fuel flow to the filter and check the fuel pump. There was fuel in the filter and the lines on either side of it, and the fuel that was in the filter flowed freely through in the correct direction when I drained it. However, it seems like there isn't much fuel flowing to the filter in the first place, so it may be a blockage at the pickup in the tank, or in the line itself.

After 20+ years, some more detailed maintenance beyond changing an air filter, oil and filter, spark plug(s) and fuel filter is past due.
Change the fuel cap, clean out the fuel tank, replace all fuel lines, clean the carb.

Yeah, I'm going to replace all the lines. They're definitely getting long in the tooth. The cap seems fine, though.

One of the best at least yearly activities you can do for any “small” gas engine that will sit unused for a prolonged period, is drain the fuel tank (or sacrifice a tank full of fuel to be drained in the spring) then run the engine until it will not run any longer.

I run it all year round - Mower, leaf blower, snowblower - And in the spring and fall when it may sit for a bit I do leave it with a full tank.

 

[dirttoys]

Well... Before I pulled the carb apart I decided to replace the fuel filter and check for fuel flow to the filter and check the fuel pump. There was fuel in the filter and the lines on either side of it, and the fuel that was in the filter flowed freely through in the correct direction when I drained it. However, it seems like there isn't much fuel flowing to the filter in the first place, so it may be a blockage at the pickup in the tank, or in the line itself.

Yeah, I'm going to replace all the lines. They're definitely getting long in the tooth. The cap seems fine, though.

I run it all year round - Mower, leaf blower, snowblower - And in the spring and fall when it may sit for a bit I do leave it with a full tank.

See #8 LOL

Sounds like you are on the right track!

Best,

ed

 

[macindude]

Rebuilt the carb, worked OK for the first hour but then would quit again, and if you let it cool down for a few hours it'd be back to working fine again. Replaced the ignition coils. So far so good...

 

[Williy]

Ignition coils get the specs for whats on your machine
then check the internet you can save money this way.
The fuel pump from amazon $10 and then changed out
the rubber hoses with clear plastic hose you can see if
you have any dirt etc. put choke on all the way hit starter
and it starts right away eliminates cranking

willy

 

[PILOON]

Thought I read it stopped suddenly without sputtering.
That, to me, suggests ignition related be it a switch, coil or a grounding wire and possibly the coil.
With age I'd be looking for abraded wires grounding out.

Fuel issues generally result in erratic running or sputtering.
Another possibility is a chunk of carbon at the spark plug gap.

 

[banjodunn]

Check to see if you have a fuel shutoff solenoid on the bottom of the fuel bowl on the carby you should hear it click when you turn the ign on if not check for power supply to it or a bad solenoid

Jon

 

[kirkawilson]

See #14.

 

[macindude]

Sigh.

After the carb rebuild it would run for a half hour or an hour and quit until it was cool.

Replaced the ignition coils and it ran fine for the rest of the summer.

Went to put the snowblower on it, it fired up and I shoved the choke in... Too fast. I've done that plenty of times before. But then I couldn't get it to go again, and I thought I just flooded it. Got distracted by another project, let it sit for several days, tried again... Nothing. Won't start. Squirting starter fluid into the carb makes it run for as long as it has starter fluid to burn, so it's some kind of fuel delivery problem.

Here we go again.