Runs for a few minutes...

[gerry100]

Yardman 42" lawn tractor w 20HP Intek ( 13at604g755).

Started having problems running after sitting so I thought it wa swater/condensation in the gas but now I'm not so sure.

Starts up and runs well and mows for about 3-4 minutes and then loses power and sputters.
After sitting it will repeat the process.

Fuel filter seems oK.

Carb Problem? before I get into that I'm looking for inputs.

Thanks in advance.

 

[tmajor]

Fuel filter seems oK.

What does than mean? Can you blow through the filter? Can you get gas through the filter?

I just changed the filter on my ZTR about a month ago. It didn't have that many hours and it looked fine. But I couldn't blow through it, and of course the gas wouldn't go through it, either.

How about with the fuel tank cap off? Maybe it's not getting any air into the tank.

 

[zman007007]

if your filter is fine. its sounds like your float may be sticking in the almost closed position. zman

 

[Fixemall]

Ah yes the 20hp Nightmare...see if it has a wire to the bottom of the carb bowl, chances are it does. Unplug it and see if it changes it's behavior and report back.

 

[mwb]

Ah yes the 20hp Nightmare...see if it has a wire to the bottom of the carb bowl, chances are it does. Unplug it and see if it changes it's behavior and report back.

+1 - that is a fuel shut off solenoid apparently to stop backfires when you shut it off. The solenoid on mine quit so I removed the solenoid and cut the push pin off so the fuel was always 'on'. Removed wire and it has been flawless for 10 years. I also dropped the idle speed so it wouldn't backfire

Put new fuel filter on ($4?), remove carb bowl - gas should be running freely if the float (needle) is free (not stuck). You probably have some buildup or dirt in the carb. Add some "seafoam" to your gas and give it a chance to clean it out.

 

[zman007007]

If he unplugs the wire he will have the same problem, because the fuel will be shut off to the carb. zman

 

[Raindem]

I had a very similar problem and it turned out to be a blade of grass that had somehow made it into the fuel line. When the tractor was running it got sucked to the fuel filter inlet and blocked it, thereby stalling the engine. When the tractor was shut off I guess the blade of grass floated elsewhere and allowed fuel to pass and the tractor to be re-started.

 

[gerry100]

replaced the fuel filter ( it was due) and it didn't make a difference.

It seems to run well until I load it with the Mower ( PTO ) on and then in runs for a few minutes before it bogs/stalls with gray smoke.

If I disengage the PTO it sputters and then revs up to a smooth idle.

I'm going to unplug the backfire solenoid and give it a try.

Then we'll go to carb cleaner.

Thanks and I'll report back.

 

[gerry100]

Unplugged the solenoid and it wouldn't start. I guess you have to cut of the connector and close the circuit or remove and mess with the solenoid.

Before I do that I'm going to run some sea foam thru it.

 

[mwb]

+1 - that is a fuel shut off solenoid apparently to stop backfires when you shut it off. The solenoid on mine quit so I removed the solenoid and cut the push pin off so the fuel was always 'on'. Removed wire and it has been flawless for 10 years. I also dropped the idle speed so it wouldn't backfire

Did you read this? If you want to disable the solenoid you have to remove the pin.

Zman also stated this