# overflowing carb Farmall h



## omiimiish (Oct 19, 2009)

Every year the same thing. The carb on my Farmall H overflows with gas. It won't start. I pay someone to come "look at it". He takes it apart puts it back together and starts right up. Last year I thought I would get smart and have it rebuilt at a local implement dealer. Worked great most of last year. Then same issues. This year I tackled it my self thinking must be the needle valve above the float. Everything looks clean and happy inside. Still have it apart.

I am out of ideas and ready to sell my perennial headache.

Any ideas?


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## PeteNM (Sep 18, 2003)

I wouldn't be in any hurry to sell just yet. It should have an updraft Zenith carb on it. I would check everything to do with the float and needle valve. It may just need adjusted or could be hanging up. Check the needle valve and make sure it will seal. Make sure every thing is free and will move OK. I have seen the float that was full of gas and not able to float properly. Remember if the needle valve seats properly, gas can't leak.

Good luck !!


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## omiimiish (Oct 19, 2009)

no gas in the float, i will take apart the needle valve. Every time I go to turn it over gas pours out the vent hole on the bottom of the carb.


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## jhngardner367 (Apr 5, 2011)

Install a filter,between the carb,and pump,and check the fuel tank for rust.
I t sounds as if the needle is getting jammed open.


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## omiimiish (Oct 19, 2009)

took apart the needle valve. very clean. I have a filter before the carb after the bulb. a little film but very minimal.

I am not very knowledgeable about carbs, but this one is so basic. I can not find a reason for it not to work. I have put it back together in hopes it will work.


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## jhngardner367 (Apr 5, 2011)

Have you checked the fuel pump pressure ?
It should be 4 to 7 psi. Any more than that,it will blow the needle off the seat.


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## omiimiish (Oct 19, 2009)

farmall H is gravity. From tank to carb


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## Country Boy (Mar 18, 2010)

These are gravity flow systems, John. The tank is mounted several inches above the carb. May I ask what fuel you are running in your tractor? Ethanol is a big no-no on older tractors, and oxygenated fuel is also terrible for them. They weren't designed for running those types of fuels and they cause a lot of headaches with the fuel systems. They just had an article in one of my dad's tractor collector magazines on fuel related issues with old tractors. See if you can find "off road" fuel with out ethanol if you aren't already running it.

As for your leaking issue, the "Vent" you speak of on the bottom of the carb is a drain for the air inlet so when fuel leaks into or builds up in the air inlet, it has a place to drain out. I know if I crank my H over with the choke on for too long, it will leak gas from that area. My H has a Magneto for the spark rather than the battery coil ignition on later models. Do you know which system you have? The Mags can have a weak spark or a poorly timed spark if the magnets get weak or the spark advance gets sticky. That'll make it hard to start and flood more easily.

I'd start by checking into your fuel. The stuff you get at the stations these days is garbage for older equipment.


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## omiimiish (Oct 19, 2009)

farmall H is gravity. From tank to carb


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## jhngardner367 (Apr 5, 2011)

YUP! missed that bit of info!


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## omiimiish (Oct 19, 2009)

I do use ethanol gas at times I am trying to use the highest octane which by us is the only grade with no ethanol. I do have a coil, the tractor is converted to 12 volts. Spark will be my next step if it does not start.


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## sixbales (May 18, 2011)

omiimiish,

I suspect that you need to put more hours on your tractor. Start it and run it about to splash the oil onto all internal components. Monthly basis at a minimum. Weekly would be better. Letting the tractor sit idle is not good for the engine.

This modern day gas with ethanol degrades fairly quickly. If you don't burn it off, and replenish with new gas, you bring this problem on yourself.


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