Farmall F-12 Hard to start and suddenly stalls

Anonymous-0 · Apr 25, 2014

Hi, I just finished restoring my 1937 Farmall F12. It is hard to start, even if it has been running earlier and it keeps stalling and then won't start. The timing is right on, just a hair after TDC and it is getting fuel, with a rebuilt fuel pump, and good spark with new plugs which are the right kind. I did put in a new float which i was thinking may be the problem but i left it at the same setting as the old float was. I did get it to start after it stalled today but it immediately flooded itself and stalled again. The gas tank has been cleaned but is still a bit dirty so what im trying to get at is what is the most likely problem before i begin tearing it apart again? The filter before the pump seems to be taking out any dirt and it was running and driving just a bit rough before it stalled. For some reason the pump seems to pump a lot of gas in just one stroke but I've been told its normal. I dried the plugs and cylinders and it started but then stalled again. It was running fine for about 5 minutes but this was the first time using it with the gas tank. Thanks for any thoughts and suggestions.

Mike Androvich · Apr 25, 2014

Make sure your fitting at the top of the gas tank that the fuel line from the pump hooks to is open back into the gas tank. If this is plugged that excess gas from the fuel pump has nowhere to go except the carb. That could be your flooding problem.

rustred · Apr 25, 2014

yep, that's a for sure, make sure the bypass is operating.

jal-SD · Apr 25, 2014

If its like my F-12, you also have to hold your mouth just right and it (the tractor) has to be in the right mood. Then it will start of the 2nd or 3rd (or perhaps 545th) pull. A "chain starter', however, works every time. Just connect a log chain between the front of the F-12 and the rear of the 4WD pickup, put someone reliable behind its wheel, and have them put it in low range, low gear. Agree on go & stop signs. Then climb on the '12, put it in 3rd gear, make sure the mag is not grounded, make sure the gas is on, set the throttle at 1/3, put the clutch in, give the driver the go sign and after the '12 starts to move, let the clutch out. When it starts (usually in about 50 feet or less), Put in the clutch, and give the driver the stop sign. Unhook and don't let the '12 kill until you want to shut it off after the job is done, or you will have to repeat the above process. (BTW, this process works for a '14, too.) I've been told that even with every thing in perfect order, the '12's & '14's are the hardest crank starting tractors IH ever built. I believe it. (My $0.02 worth. jal-SD)

rustred · Apr 25, 2014

I think you have a problem with that tractor. I always thought man these sure start easy. that little tiny engine in my W12 starts so easy. you can shut it off and just pull up on the crank slowly and it fires up as soon as the impuse trips. I can turn it so slow that you barely see the crank move and it fires right up. have demonstrated this many times to people at parades.

Anonymous-0 · Apr 25, 2014

Thanks for the tips. I hadnt thought of the bypass so I will make sure to check that, if not i will just check the float and make sure it isnt stuck. It was working okay before so that might be it. Thanks.

Athol Carr · Apr 26, 2014

There is a fine gauze filter in the inlet to the carburetor. Make sure it is clean. If it is a kerosene/distillate engine then if thr starter tank is in the hood, later F-14 and all other 12 series, then there is gravity feed for starting. If it has the gasoline tank in the rear of the main tank then there is the small header unit standing up through the hood ahead of the fuel tank where it would be possible to prime the system with gasoline for starting. However, if is a straight gasoline tractor (of any of the 12 series), then if the carburetor is dry it can take a whole lot of cranking before one is able to smell gasoline in the exhaust. Most of the fuel from the pump goes straight back to the tank and only some from the T fitting ahead of the tank makes its way to the carburetor. Once they are running they are great but I have spent considerable effort cranking before starting my O-12 if it has been sitting for a while.

James Williams · Apr 26, 2014

Eliminate your fuel pump,by using a lawnmower tank and gravity feed it to the carb.If fuel pump is pushing to much gas your flooding.If pump is pushing to much gas start putting extra gaskets behind pump to act as a shim.Did you install new needle valve and is your float working properly.Timing is critical

jimmy

Farmall F-12 Hard to start and suddenly stalls

Anonymous-0

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Mike Androvich

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rustred

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jal-SD

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rustred

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Anonymous-0

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Athol Carr

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James Williams

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