Super A: Gas drips from carb - gas cap to blame?

Bruce Brittain · Jul 10, 2012

Gas sometimes drips from the carburetor, especially on hot days. It also pees out in a steady stream from the carb and air filter cup when starting. But the tractor runs okay once it starts. I'm wondering if the gas cap is not properly vented, and is pressurizing the gas tank.

According to the owner's manual, the tractor is supposed to have a low, vented gas cap ("Buy clean fuel, keep it clean"). Instead, it has a tall cap ("Open slowly, pressure'). Could this be part of the problem?

Whatever the cause, this has apparently been going on for some time. I changed the oil in the air filter cup when I bought the tractor, and was surprised to find that there was gas in the cup instead of oil. So I guess gas has been drawn into the air filter, diluting the oil, then the gas/oil mix has been dripping or running out of the cup. Probably not a real safe situation.

Thanks in advance for any thoughts or advice.

--Bruce

mkirsch · Jul 10, 2012

In two words: Absolutely not.

For one thing the gas cap is vented, and even if the vents are plugged, it would have to be a VERY hot day to pressurize the tank.

There is something wrong with the float and/or needle in your carburetor. The carburetor needs to be taken apart, cleaned, rebuilt, and adjusted.

The tall gas cap is the correct triple-baffle version that all IH tractors should be equipped with these days regardless of what was on it when it was new. The short gas cap is a fire hazard. Several people got burned apparently, so IH was forced by a lawsuit to provide the tall gas caps for free.

Red Dave · Jul 10, 2012

Either the float in your carburetor is not adjusted properly, the float is not floating, or your needle valve is not closing.

Anonymous-0 · Jul 10, 2012

Is it a Zenith or a Carter Carb? It seems that Carters have more problems than the others but they are a good carb!
Shut the gas off when you park it and it wouldn't hurt to clean the carb.

dhermesc · Jul 10, 2012

It could be your gas cap but it is very doubtful. The easiest way to check is to remove the cap when its dripping - if you hear an audible escape of air you know your cap's vents are clogged.

Even if that were the case I doubt (but anything is possible) that it would build up enough pressure to force fuel through a properly adjusted carb.

JRSutton · Jul 10, 2012

agree with others - but easy enough to check if you want to be sure - just remove the cap.

I'm pretty sure you'll find the problem doesn't go away.

Those carbs do flood easily - it's most likely your floats either aren't set right or leak, or the needle valve is junk. Could be junk in the valve keeping it from closing.

Either way - it shouldn't really be a big proglem if it doesn't leak while running.

Instead of turning the tractor off by the kill switch - shut the gas off at the valve and let it run itself dry.

It's a good idea to do it that way anyways, for several reasons. When you're ready to start it - turn the gas on and start right away before it starts dripping.

Not to say you shouldn't attempt to fix the problem - but that'll at least hold you over more safely until you do.

old · Jul 10, 2012

About as likely as finding a 3 dollar bill that is real. But you do have a very good chance that it is dirt/rust in the needle seat or the carb or a sticking float and one that is not adjusted as it should be. If it is dirt/rust and easy maybe fix if pull the carb drain plug then let the flue flow for a few minutes. Catch the gas to look at it and so you can use it. Also one way to do it is turn the gas one, count to 3o turn it off, start the engine then turn the gas back on real fast and your problem should sort of go away

Bruce Brittain · Jul 21, 2012

Thanks to all.

It turns out that I have a Carter UT-series carburetor. (I had to take it off the tractor and clean the junk off the outside in order to find a manufacturer's identification.) I have now purchased a carburetor rebuild kit, and will tear into it the next chance I get.

Thanks again.

--Bruce

Super A: Gas drips from carb - gas cap to blame?

Bruce Brittain

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mkirsch

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Red Dave

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Anonymous-0

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dhermesc

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JRSutton

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old

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Bruce Brittain

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