Briggs Carburetor Leak

G6 at Snook, TX · Nov 30, 2013

This carburetor leaks at idle, but has good power and pick-up when switching to a high idle setting on the welder. It is a Briggs motor from the mid 1980s. With the welder sitting at such an angle should the carburetor leak while running? Or not? I don't recall it ever doing that before.

Thanks for the comments.

NDG

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Rich Perry · Nov 30, 2013

It doesn't leak just sitting? Or do you have a shutoff for the gas?
The angle it is sitting on looks like the float would be all the way to the top of the bowl and wouldn't shut the gas off. So the bowl will fill completely with gas and with today's gas it may have made a hole in a gasket.
The needle valve on this carb is on the end where the fuel line is located. Try leveling the motor and see if it still leaks.
Just my2¢
Rich

G6 at Snook, TX · Nov 30, 2013

I have a shutoff for the gas. When it does leak it is through the welch plug on the back for the carb. It is the lowest point. Is this the type of float I could manipulate to lessen the flow? Or is that fixing it until really breaks?

jeffcat · Nov 30, 2013

OK I have several Briggs engine with this setup. Take the carb off. REMOVE the main jet and fuel tube FIRST. the carb can now be taken apart. You should have a thin paper type gasket that probably is wrinkled. Get a new one and put her back together. Also check your float is not bad. There maybe a leak in it and the float is too low. These carbs are dirt simple so just be careful and fix it.

Rich Perry · Dec 1, 2013

Sorry, I had a brain-fart yesterday.
When the needle valve is uphill the amount of fuel in the bowl will be less than at level.
If the needle valve has even the smallest bit of dirt in it, it may not close all the way and cause the bowl to overfill.

Rich Perry · Dec 1, 2013

As Jeff said these are fairly easy to work on and clean.
When you remove the bowl you can also check to see if the needle valve is closing properly by squirting carb cleaner through the fuel line to the carb and carefully raising the float to see if the flow stops. Do this gently so you don't bend the float arm.

G6 at Snook, TX · Dec 1, 2013

Jeff,

Since you have had experience with these carburetors, at that angle on the trailer, the carburetor should not leak when all is right? That is as low as the jack stand will go without burying the tongue in the ground.

Billy Shafer · Dec 1, 2013

Gasket has been my main problem with them. Also may have some trash under the needle.

G6 at Snook, TX · Dec 24, 2013

Had some time to mess with the carburetor, but continued to leak. I guess I flooded the engine enough (or fixed it enough) that the machine will not start at all. After the first time I pulled it off, it ran but still leaked. After that, just a few hiccups. May have fouled the plug. Gaskets wet, I guess I should wait until tomorrow to fool with it more.

It appears that the needle is not seating on the rubber all the way to close it off. Also, the little rubber o-ring that the needle seats against, has a smooth side and a ribbed side, which point to the needle? Any other suggetions? Admittedly, I am not an expert at carburetors, though this is very easy to take apart.

IH2444 · Dec 24, 2013

(quoted from post at 16:52:46 12/24/13) Had some time to mess with the carburetor, but continued to leak. I guess I flooded the engine enough (or fixed it enough) that the machine will not start at all. After the first time I pulled it off, it ran but still leaked. After that, just a few hiccups. May have fouled the plug. Gaskets wet, I guess I should wait until tomorrow to fool with it more.

It appears that the needle is not seating on the rubber all the way to close it off. Also, the little rubber o-ring that the needle seats against, has a smooth side and a ribbed side, which point to the needle? Any other suggetions? Admittedly, I am not an expert at carburetors, though this is very easy to take apart.

ribbed side goes towards the bottom of the seat.

G6 at Snook, TX · Dec 25, 2013

Got it running again. Plug was fouled. Turned the rubber o-ring around as suggested, and it fired up easily. It ran fast, slow, and is set.

However, I have the habit of running the motor out of gas due to bad gas issues, and it leaked again. Appeared to be that the needle is not closing shut unless it is getting a full shot of gas to force the float up. The float does not have a leak in it.

Do you normally run motor out of gas on a machine like this? Or let the gas stay. Also, there does not appear to be a drain on it like other carburetors I have used. Is that true?

Bob · Dec 25, 2013

I have a twin to that engine on a grain auger and shut off the gas all the time and let it empty the carburetor and stop, with NO problems when I need it again.

I would suspect you float is wedging/sticking down.

Some carbs have a "float drop" setting to stop this problem, I can't remember if the Briggs does.

If you look closely, there MAY be a mark on the float or float bowl where the float touches and sticks.

A little careful "adjusting" of the float may cure that.

As far as a drain, unscrewing and removing the COMPLETE main jet needle assembly will allow the float bowl to drain.

Briggs Carburetor Leak

G6 at Snook, TX

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Rich Perry

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