Super M Farmall (Gasoline)

Dale Thomas · Aug 27, 2013

I have a Super M Farmall (gasoline) that we rebuilt 2 years ago. We have had problems the last few rides with the intake manifold just above the carb. freezing up which makes the engines not run smoothly when trying to drive it. Have re-set the vales, new pts./condenser, checked timing and reset the air/fuel mixture on carb. When the tractor is running rough it also has a tendency to flood.

I assume this is vapor locking. Any ideas to solve this problem is welcomed.

David G · Aug 27, 2013

What is the temperature and humidity when this happens? It sounds like the manifold is icing up.

Carlyle hoffman · Aug 27, 2013

I would say it is FREEZING UP, not vapor locking. The condensation on the outside of the manifold gives evidence that the inside is very cold,hence freezing the air fuel mixture, causing it to starve for fuel hence the ruff running engine cond. Vapor looking is caused by extreme heat around the manifold. You have just the opposite cond. As to a solution at current i have none.

Ellis Kinney · Aug 27, 2013

Your tractor problems are not a result of the manifold freezing just above the carb. I have 3 M Farmalls and they all do that, summer or winter. Ellis

Janicholson · Aug 27, 2013

The carb is freezing internally the ice builds up on the vanturi and the throttle plate area where the change in pressure is greatest. The normal solution is to work the tractor hard. But on a ride it is not possible. Making an intake stove around the muffler and piping the heated air into the intake stack (where the precleaner or dome is) will do the trick. Most mid 60 to late 80s cars had them to prevent that from happening. The ice causes rich running and black smoke. Jim

VicS · Aug 27, 2013

I had a 4010 gas once that did this real bad. It did have a LP manifold. I ran 3/8 copper tubing around the neck about 4 times. Hooked it up to the antifreeze, just like it was a heater. I also wrapped the coils with duct tape. Fixed it but, probably not the look you want. Another thing you can do is shut the motor off when you aren't traveling. This will let it (heat sink) sometimes this is all you need to do. Vic

Wayne in MN · Aug 27, 2013

Get the engine temp up to normal! Unless this is a "working" tractor, you may have to cover part of the radiator to bring the temp up. The fan will blow enough hot air to keep the carb warm.

Dale Thomas · Aug 27, 2013

The tractor does it on 100 degree days or 40 degree days.

Dale Thomas · Aug 27, 2013

Thanks for the excellent posts. I will develop some type of process to raise the manifold temperature which should save the problem.

Thanks for all the help. It is appreciated.

Bill(Wis) · Aug 28, 2013

Carburetor icing can occur on hot, humid summer days as well as on colder days due to the rapid expansion of the fuel air mixture in the venturi section of the carburetor."Expansion is a cooling process" and especially so when the expansion is very rapid. Aircraft recips w/carbs combat this with an especially designed carburetor heat system. Several of the posts have mentioned fabricating something to do this on your M but what will probably work for you is to try an anti-icing agent additive in the fuel or just put Mobil Super in it. Wouldn't change the appearance of the tractor in any way in case the Tractor Police show up at the parade.

Super M Farmall (Gasoline)

Dale Thomas

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David G

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Carlyle hoffman

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Ellis Kinney

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Janicholson

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VicS

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Wayne in MN

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Dale Thomas

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Dale Thomas

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Bill(Wis)

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