Farmall H with a M carburetor

Baum604 · Jul 17, 2012

Last year I bought a '41 H and the previous owner for some reason or other put a M carburetor on it. It runs well with it and can't see any problems using it, but for the sake of having the correct carburetor, I want to put a H carb back on it. The problem I found with putting the H carb on the manifold is that the oval surface containing the two holes for the supporting bolts on the side of the manifold is larger than the mating surface of the H carburetor. With the M carburetor the mating surfaces are the same and the edges are flush with each other while with the H carb they are not. The picture shows it with the M carburator on it.

I noticed that the holes on the manifold side are elongated and will allow the H carb to bolt to it. Is this the way it should fit? I wasn't able to see another H to compare it to that has the same type of manifold. The manifold that I have is not for a distillate but one strictly for gas.

Thanks

Janicholson · Jul 17, 2012

Many replacement Manifolds are designed to have spacing for both the M style carb, and the original H carb. The Super H carb looks a lot like an M carb but is smaller in flow, and different internally. You might have a SH carb. Either way you are goint to need to find a OEM style manifold to get back to the best fit and original style connection. If originality is the intention, that is probably the way to go. Jim

DeltaRed · Jul 17, 2012

That looks like a Super H carb/manifold.Are you sure
someone in the tractor's past did'nt swap engines or
something.Shs used the M carb.

DeltaRed · Jul 17, 2012

I was wondering if the SH carb had smaller jets/venturi,etc.Thanks

Baum604 · Jul 17, 2012

The previous owner told me he replaced the manifold and carb. He said that the carb was from a M, so that is what I am going from when I say that it is a M carb, I don't know the difference. It is though the original engine since it has the same serial number stamped on it as the bell housing plate.

Baum604 · Jul 17, 2012

Here is another picture of it if it helps.

pete 23 · Jul 17, 2012

The aftermarket manifold fits both H and Super H. I
have one on one of my H tractors with the H
carburetor. The only thing I don't like is there is
that difference of the bore size in the manifold
compared to the bore of the H carburetor. I would
prefer a original gas manifold but they are really
hard to come by in good condition.

Dean Olson · Jul 17, 2012

Looks like an M carb to me. The SH carb has the choke control
inside against the block.

I agree with the others that your manifold is aftermarket. The H
carb should bolt right up and not be an issue, other than
appearance.

I have a SH with an M carb and the venturi and jets are a little
bigger. It creates a running rich issue at low idle. Other than that it
runs great with good power. I have a SH carb that I will rebuild and
install some day.

armand tatro · Jul 17, 2012

You say it runs good with the "M" carb. The old adage applies here: If it aint broke don't fix it!! As long as it runs and preforms well I would use it and enjoy it!! Armand

rustred · Jul 17, 2012

the super h and super w4 will have a carb that looks like an m carb but is smaller. the m carb will not directly bolt up to the h manifold.

rhtx55 · Jul 17, 2012

You don't NEED a new manifold & carb, but if you want it original you will need to change it back to the original part numbers. The manifold heat shield will be almost impossible to find but aftermarket ones are available.

One the other side of the engine what number is stamped above & behind the oil filter cannister next to the firing order? C---

An original used manifold & carb should be readily available as many of these tractors were built, but before you go any further realize the replacements you purchase may be in much worse shape and need quite a bit of work, much more than the ones you already have, and may not perform near as well, BUT they will be originals.

A 39 H is well worth restoring, if you are going for a total original parts restoration, consider purchasing a 39 h parts tractor, you are going to need it ..trust me.

Baum604 · Jul 18, 2012

I never thought about an aftermarket manifold. I am going to leave it be, doesn't bother me with it on. It was puzzling me how this carb bolts up flush and the H carb wasn't flush.

Thx for the help.

Farmall H with a M carburetor

Baum604

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Janicholson

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DeltaRed

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DeltaRed

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Baum604

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Baum604

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pete 23

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Dean Olson

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armand tatro

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rustred

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rhtx55

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Baum604

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