# Briggs and Stratton Generator fuel shut-off valve issue?



## rehoman (Dec 2, 2020)

My B&S Generator runs fine. But when I close the fuel valve it stops the engine immediately. It used to take 5 minutes before it used up all the fuel in the carburetor. Now it shuts off immediately. Any idea what could cause this?

Thank you,
rehoman


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## tabora (Sep 6, 2018)

Turn off the valve and then unscrew the sediment bowl below it. Place a container underneath to catch the fuel and open the valve and let a 1/4 cup or so of liquid drain from the tank into the container. Check for water or other contaminants in the container and in the sediment bowl. Turn off the valve, perform the fuel valve maintenance as shown on page 11 of the manual, reassemble and then open the drain screw on the carburetor bowl. Repeat the flushing process. See it that helps or not and report back.


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## iowagold (Jan 22, 2020)

also check to make sure the tank vent is clear.
drop the carb fuel bowl and make sure you are getting full flow out of the fuel needle area.
it should have a pretty good 1/16 to 1/8 inch of flow if the needle is removed.
also check the fuel lines they could have gone bad inside with age.
and check the carb bowl for rust...
and fuel tank for rust or trash in the bottom.


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## rehoman (Dec 2, 2020)

tabora said:


> Turn off the valve and then unscrew the sediment bowl below it. Place a container underneath to catch the fuel and open the valve and let a 1/4 cup or so of liquid drain from the tank into the container. Check for water or other contaminants in the container and in the sediment bowl. Turn off the valve, perform the fuel valve maintenance as shown on page 11 of the manual, reassemble and then open the drain screw on the carburetor bowl. Repeat the flushing process. See it that helps or not and report back.
> View attachment 8505


Thank you. I will definitely try this, but fuel is definitely getting to the carb even now. Once the fuel is in the carburetor bowl, shouldn't it still run for several minutes after I close the valve? The engine shuts down immediately after closing the valve now. It never used to do that.


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## iowagold (Jan 22, 2020)

rehoman said:


> Thank you. I will definitely try this, but fuel is definitely getting to the carb even now. Once the fuel is in the carburetor bowl, shouldn't it still run for several minutes after I close the valve? The engine shuts down immediately after closing the valve now. It never used to do that.


yup
should be a few min of run unless it has a electric shut down like on the honda eu2000i gens on the fuel valve.


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## tabora (Sep 6, 2018)

Alex11 said:


> _Valves_ control the flow of _fuel_ vapor into the combustion chamber and the flow of exhaust gases leaving the engine.


And lots of other things, like liquid fuel from fuel tanks and water from faucets. Your point???


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## rehoman (Dec 2, 2020)

iowagold said:


> yup
> should be a few min of run unless it has a electric shut down like on the honda eu2000i gens on the fuel valve.


There's no electric switch incorporated into the fuel valve, which is why my issue doesn't make sense to me. The only thing I can guess is that very little fuel is flowing past the valve, so there is never more than a few drops of fuel in the bowl. I'll try to clean out the filter tomorrow and see if it helps.


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## iowagold (Jan 22, 2020)

sounds like a bad float


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## drmerdp (Apr 10, 2018)

iowagold said:


> sounds like a bad float


Yeah, sound like the bowl is just barely filled enough to run when the valve is open.


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## iowagold (Jan 22, 2020)

bad sticking needle??
or a float set to wrong height.


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## rehoman (Dec 2, 2020)

Thank you all for your replies. Today I removed the sediment filter and it was perfectly clean. I didn't have a chance to run it afterwards but suspect the problem will still be there. 

I'll run it tomorrow and find out. If it's an issue with the carb, I'll have to take it to a pro. That's above my pay grade.


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## tabora (Sep 6, 2018)

rehoman said:


> If it's an issue with the carb, I'll have to take it to a pro. That's above my pay grade.


Surely not... I did my first carb cleaning when I was 6 years old in 1962, and long before there was something called the internet to help out. Take a look at some carb cleaning videos on youtube. It's really very easy to do.
Metal carb




Plastic carb


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## rehoman (Dec 2, 2020)

Tabora, I appreciate your response and encouragement. I'll watch the videos. 

An interesting update: My fuel cap has a rubber vent line coming out of the top which is routed to the carb. I assume this has to do with vapor emissions. In any case, I loosened the gas cap and that seemed to enable the engine to run longer after I closed the fuel shutoff valve. Iowagold had recommended checking if the tank vent was clear. I'm not sure if this means anything.


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## iowagold (Jan 22, 2020)

i would do away with the cap on there and go a old school direct to air vented cap..
and cap off the vent port on the carb.
sounds like the carb is sucking back on the fuel feed through the tank via the hose on top of the oem cap.


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## rehoman (Dec 2, 2020)

iowagold said:


> i would do away with the cap on there and go a old school direct to air vented cap..
> and cap off the vent port on the carb.
> sounds like the carb is sucking back on the fuel feed through the tank via the hose on top of the oem cap.


Could I test your idea by disconnecting the rubber tube from the gas cap and then sealing it closed with a binder clip?


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## iowagold (Jan 22, 2020)

that cap needs to vent unless the tank has another vent built it.
replace the cap with a venting cap is the solution for that.

but the carb needs a sealed cap where the old hose was connected.


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