My Farmall M Tractor, propane powered

Tom Box · Oct 2, 2013

I recently aquired an old Farmall Tractor M which is
powered by propane. The enginge turns over good but
It will not fire. I filled it with propane. What
should I look for , for trouble shooting. I noticed
that when I open the drain cock on the propane
regulator, some prestone started draining out. Is
it supposed to have prestone and water in the
regulator? I need someone to tell me how to trouble
shoot and check it out.

Owen Aaland · Oct 2, 2013

(quoted from post at 17:56:28 10/02/13) I recently aquired an old Farmall Tractor M which is
powered by propane. The enginge turns over good but
It will not fire. I filled it with propane. What
should I look for , for trouble shooting. I noticed
that when I open the drain cock on the propane
regulator, some prestone started draining out. Is
it supposed to have prestone and water in the
regulator? I need someone to tell me how to trouble
shoot and check it out.

The convertor/regulator uses coolant to heat the liquid propane to convert it to vapor.

Check the electrical system first to be sure you are getting spark at the plugs.

Start by having both tank valves closed. Crank the engine to make sure it is not flooded. If it was flooded it will fire a time or two as it clears the excess fuel from the system. Next open the vapor valve. If it is real quiet you should hear fuel go through the valve just as you start to open it. The flow should stop as soon as the pressure equalizes. There should be no fuel leaking through the regulator. The regulator is opened by vacuum as the engine cranks. (Either 1 1/2" or 1/2" water column depending on what regulator is installed.) If the engine still doesn't fire and you have made sure it is not flooded you can try putting just a bit of gasoline in the carburetor and see if it will fire.

Once the engine is running and has started to warm up you can open the liquid valve.

D beatty · Oct 2, 2013

I not famillar with the regulator on an M but do have a lp combine engine and the regulator on it is hooked up to cooling system to warm fuel. If yours is hooked to cooling system there must be a internal leak of coolant in regulator.

Owen Aaland · Oct 2, 2013

Since he posted that coolant came out when he opened the drain cock I assumed that it was a drain on the coolant side. There could also be a plug on the fuel side to check pressures.

CenTex Farmall · Oct 2, 2013

Do you have an Ensign regulator on the tractor? They have a drain cock on the water jacket side. The regulator also acts as a heat exchanger to boil off liquid propane under high demand situations.

Can you post a picture of the setup?

Tom Box · Oct 3, 2013

Thanks guys for all the information. I will try
closing both valves and then slowly open the vapor
valve. The man I bought it from said the reason it
will not run is because the propane line junction
coming out from the liquid and vapor valves are
kinked and he says he does not believe enough
propane is getting through for the tractor to run.
When I look at the kinked area of the line he is
talking about, it appears to me that propane can
get through there. It is not totally kinked to
where propane cannot get through there. I also
open the drain cock on the inline filter below the
kinked area and propane comes out there so I don't
think that is the problem. I will now check to see
if it is getting fire.

My Farmall M Tractor, propane powered

Tom Box

New User

Owen Aaland

Well-known Member

D beatty

Well-known Member

Owen Aaland

Well-known Member

CenTex Farmall

Well-known Member

Tom Box

New User

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