Carburetor drain plug leak

TerryB Illinois · Jun 14, 2018

I noticed gas was dripping from my carburetor drain plug today. I thought it might be a little loose so I tightened it up a bit, but this did not help the problem. I tightened a little more and still no luck. With all the brain power here, I know someone can tell me how to stop this leak. Any help would be appreciated.

JMOR · Jun 14, 2018

(quoted from post at 13:44:24 06/14/18) I noticed gas was dripping from my carburetor drain plug today. I thought it might be a little loose so I tightened it up a bit, but this did not help the problem. I tightened a little more and still no luck. With all the brain power here, I know someone can tell me how to stop this leak. Any help would be appreciated.

t is a tapered pipe fitting and if it has been overtightened in the past it may have cracked the carb bowl. Clean and examine carefully. If no crack, & you know the proper way to apply, teflon tape should work.. Keep it off the end threads! There are some better gas resistant sealers, too.

Roger in Iowa · Jun 14, 2018

Isn't there an overflow drain near the drain plug, so if the float is too high or needle
valve is not shutting off, it lets the gas overflow?

Tractoman · Jun 14, 2018

(quoted from post at 12:19:10 06/14/18) Isn't there an overflow drain near the drain plug, so if the float is too high or needle
valve is not shutting off, it lets the gas overflow?

Make sure it's not a stuck float causing gas to run out the choke shaft and dripping down the back side of the carb appearing to be coming from the drain plug.
Don't ask how I know this.

Den N Ms · Jun 14, 2018

Terry,Be sure there is no crack in the bowl at the plug,replace the steel plug with a brass plug(will seal better). Even better would be a brass petcock to drain when needed with liquid Teflon or tape on the threads.
Pet Cock

TerryB Illinois · Jun 14, 2018

I will check tomorrow to see if the bowl happens to be cracked. I don't think that I tightened it that much to crack it but I will check. The more I think about it, I think the float may have stuck on it.

Tim PloughNman Daley RIP · Jun 15, 2018

I tend to agree with JMOR -the carb drain is a 1/8-NPT type plug. It has been boogered up either by overtightening OR someone tried to retap the carb female port with the wrong size OR someone installed the wrong size plug with a straight thread bolt. Is it a brass NPT plug or a standard bolt? I have worked on a few carbs with leaking drain plugs and the typical reason is because of the wrong size plug and/or tap was used. YOU NEED TO EITHER FIX TEH LEAK -SAFETY IS FIRST AND FOREMOST -YOU DON'T WANT TO MUCK AROUND AND HAVE TO WORRY ABOUT A LEAKING CARB RIGHT? If carb threads have not been boogered up, try a new 1/8-NPT plug. If that doesn't fix it, try a thread sealant that is fuel friendly like GASOILA -see LINK below. TEFLON tape would work in a pinch but only at the drain and nowhere else. If threads ARE boogered up, option 1 is to get it retapped for a larger plug, or option 2 buy a used carb with a known good plug and swap out the bottom halves. If N' it were me, I'd find the root cause of the leak and avoid using any thread sealant or Teflon tape.

GASOILA -THREAD SEALANT:

Tim Daley(MI)

Carburetor drain plug leak

TerryB Illinois

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JMOR

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Roger in Iowa

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Tractoman

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Den N Ms

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TerryB Illinois

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Tim PloughNman Daley RIP

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