Engine will only run for a few min?

chris1976

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Why would a engine (Briggs & Stratton) in my mower only run for a few min and then just stop? It started right up the first run then dies after a few min then i had to use starter fluid to get it to run again and it ran for 3-4 min then dies.

I don't think it would run for a few min on starter fluid alone. This mower only has 8 hours on it but it is from 2012 the gas is not from 2012 :laughing:

Is it bad gas? I'm using the same gas on another mower and it has no issues.
 

Boobala

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Why would a engine (Briggs & Stratton) in my mower only run for a few min and then just stop? It started right up the first run then dies after a few min then i had to use starter fluid to get it to run again and it ran for 3-4 min then dies.

I don't think it would run for a few min on starter fluid alone. This mower only has 8 hours on it but it is from 2012 the gas is not from 2012 :laughing:

Is it bad gas? I'm using the same gas on another mower and it has no issues.

I would first make sure the gas cap is vented OK, then if no dice, a THOROUGH cleaning of the ENTIRE fuel system, including SUPER cleaning the gas tank, replace fuel shutoff valve, fuel filter, & hoses then if no good, time for a carburetor cleaning or O/H, we have O/H and cleaning guides available for MOST Briggs engines but we will need your engine model and code numbers ...also check for a dirty air filter ... keep us up dated .....
 

chris1976

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I would first make sure the gas cap is vented OK, then if no dice, a THOROUGH cleaning of the ENTIRE fuel system, including SUPER cleaning the gas tank, replace fuel shutoff valve, fuel filter, & hoses then if no good, time for a carburetor cleaning or O/H, we have O/H and cleaning guides available for MOST Briggs engines but we will need your engine model and code numbers ...also check for a dirty air filter ... keep us up dated .....

You don't think it would be the gas? I'm not sure how old it is.

I will give it another try.

Thanks for the help.

BTW what do you do with old gas?
 

Boobala

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You don't think it would be the gas? I'm not sure how old it is.

I will give it another try.

Thanks for the help.

BTW what do you do with old gas?

In Central Florida ( dependant on location ) we have burn-pits where ya can burn most land-cleaning debris, trees, bushes, logs, paper but NO garbage or plastics ( common-sense ) I use my old gas for lighting the fire .. VERY carefully !!
 

sgkent

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Why would a engine (Briggs & Stratton) in my mower only run for a few min and then just stop? It started right up the first run then dies after a few min then i had to use starter fluid to get it to run again and it ran for 3-4 min then dies.

I don't think it would run for a few min on starter fluid alone. This mower only has 8 hours on it but it is from 2012 the gas is not from 2012 :laughing:

Is it bad gas? I'm using the same gas on another mower and it has no issues.

what is the air cleaner like? Have you been using it in a really dusty environment, or is the air cleaner wet? I've seen this before when the air cleaner is causing the mixture to be too rich. Tight valves can cause this too but that wouldn't be the case on a new engine. But an engine stored for awhile in a damp area could get a damp filter.
 

chris1976

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what is the air cleaner like? Have you been using it in a really dusty environment, or is the air cleaner wet? I've seen this before when the air cleaner is causing the mixture to be too rich. Tight valves can cause this too but that wouldn't be the case on a new engine. But an engine stored for awhile in a damp area could get a damp filter.

I've left the air filter off and it still dies in a few min also left the gas cap loose. Changed the fuel filter fuel flow arrow towards carb right?

Think i will just drain the gas and try new fuel.
 

Boobala

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Chris .. RE-READ my post ..# 2 ....... if the carburetor linkage has NOT been fooled with and is operating correctly, and you follow the steps I outlined we can eliminate 1/2 the fuel system, and move on to the last half... it's your call ....... YES ..... arrow towards the CARBURETOR
 

Austin Healey

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I've got a similar problem with my elderly (at least 20 years) Yard-Man mower w/ 3.75 Briggs engine and Walbro carburetor.

Toward the end of this mowing season, it wouldn't start, period. So I:

--cleaned spark plug and air filter
--removed carb and confirmed that gas was flowing from the tank to the carb
--took apart carb and there was plenty of fuel in the bowl, so the needle valve wasn't stuck.
--the carb itself was reasonably clean, but a couple of small holes were clogged. Unclogged everything, cleaned w/ carb cleaner and re-assembled. The o-ring between the carb and the engine manifold was in good shape.
--put everything back together, gave the priming bulb a couple of pumps, and the engine fired right up on the first pull
--ran fine for about five minutes, then started to "hunt" mildly, then gently died. More severe hunting has been noticed for several years, but not to the point of the engine dying.
--if I push the priming bulb a couple of times, it will start immediately and run from 2 to 5 minutes before gently dying again -- sometimes after mild hunting, sometimes after running normally. This process can be repeated indefinitely, as far as I can tell.

I admit that one thing I haven't tried (yet) is to check whether the gas cap is plugged.

Also, I've never fooled with any of the adjusting screws (2) on the carb. And the throttle cable gave up the ghost several years ago, so I wired the linkage so the engine runs at approx 80 percent of full throttle, which works fine.

Any thoughts?
 

bertsmobile1

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Better than average chance you have a blockage in the fuel system, either internally in the carb or externally in the fuel supply system.
You are getting enough fuel into the engine to start it but not enough to maintain running.
The carb has 2 circuits, idle & run.
The idle circuit will flow enough fuel to start the engine but not to run at any speed above low idle.

Try starting the engine then instantly throttling down and see if it will run for longer.

Fit some sort of alternative fuel tank held above the carb.
Problem goes away = fuel delivery problem
problem stays = carb problem

As for stale old fuel, pop it in a modern fuel injected car, they will burn any trash liquid.

Go to http://outdoorpowerinfo.com/ and check the photo manual for cleaning your carb.
 
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I've got a similar problem with my elderly (at least 20 years) Yard-Man mower w/ 3.75 Briggs engine and Walbro carburetor.

Toward the end of this mowing season, it wouldn't start, period. So I:

--cleaned spark plug and air filter
--removed carb and confirmed that gas was flowing from the tank to the carb
--took apart carb and there was plenty of fuel in the bowl, so the needle valve wasn't stuck.
--the carb itself was reasonably clean, but a couple of small holes were clogged. Unclogged everything, cleaned w/ carb cleaner and re-assembled. The o-ring between the carb and the engine manifold was in good shape.
--put everything back together, gave the priming bulb a couple of pumps, and the engine fired right up on the first pull
--ran fine for about five minutes, then started to "hunt" mildly, then gently died. More severe hunting has been noticed for several years, but not to the point of the engine dying.
--if I push the priming bulb a couple of times, it will start immediately and run from 2 to 5 minutes before gently dying again -- sometimes after mild hunting, sometimes after running normally. This process can be repeated indefinitely, as far as I can tell.

I admit that one thing I haven't tried (yet) is to check whether the gas cap is plugged.

Also, I've never fooled with any of the adjusting screws (2) on the carb. And the throttle cable gave up the ghost several years ago, so I wired the linkage so the engine runs at approx 80 percent of full throttle, which works fine.

Any thoughts?

I assume since you say 3.75 that it's a Classic engine with the carb screwed to the tank.... Did you change the gasket and diaphram ???? When the carb is off you should empty the tank and clean it well then clean where the smaller pickup goes in... Some people don't even look at it much less clean it.... Then spray carb clean in the holes on the tank on the shiny machined area where the carb sets..... Clean the screens on the pickups and you should be good to go .... If you still have trouble let us know.........
 
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