H bad fuel

john4689 · Feb 8, 2015

About eight years ago the fuel went bad ,over the winter, in my 1940 Farmall H.

I cleaned the rust out of the fuel tank and cleaned the carburetor but it has never run right since then.

I have owned the tractor for 20 years and it ran perfectly when I got it.

It runs OK at 1/2 throttle ,but misses a lot at other speeds.

I have been using it as-is for the past 8 years but I am taking it to Beiler's auction in Lancaster Pennsylvania next week and I would like to get it to run a little better.

When I adjust the needle valves on the carburetor, It makes very little difference, almost as if the carb. is still halfway clogged up.

I have had the carburetor apart 3 times, over the years (most recently yesterday) and I just can't find anything wrong with it.

I suppose it could be an ignition problem. I can't remember the last time I replaced the distributor points. I filed them yesterday and have a new set on order. The spark plugs are new and the distributor cap and spark plug wires look OK.

The original 6 volt ignition coil fell apart some years ago and I fitted an old 12 volt coil that I had laying around. I used to have an adjustable resistor in the wire feeding the coil, but now I just feed 12 volts straight into it. Is it possible that the full voltage is too much?

Another odd thing - one time I ran out of gas and put a couple of gallons of 2 cycle chainsaw fuel mix in the tractor , and it ran like a champ!

Is it possible that my old tractor just won't run on the new type gasoline ?

gene bender · Feb 8, 2015

No the present gas works just fine we here in Iowa have been using it for 30 pluss yrs now. Sometimes when the old engines dont run rite seems like its easy to blame it on the fuel when itsw other stuff and not the gas.

rustyfarmall · Feb 8, 2015

(quoted from post at 06:43:01 02/08/15) About eight years ago the fuel went bad ,over the winter, in my 1940 Farmall H.

I cleaned the rust out of the fuel tank and cleaned the carburetor but it has never run right since then.

I have owned the tractor for 20 years and it ran perfectly when I got it.

It runs OK at 1/2 throttle ,but misses a lot at other speeds.

I have been using it as-is for the past 8 years but I am taking it to Beiler's auction in Lancaster Pennsylvania next week and I would like to get it to run a little better.

When I adjust the needle valves on the carburetor, It makes very little difference, almost as if the carb. is still halfway clogged up.

I have had the carburetor apart 3 times, over the years (most recently yesterday) and I just can't find anything wrong with it.

I suppose it could be an ignition problem. I can't remember the last time I replaced the distributor points. I filed them yesterday and have a new set on order. The spark plugs are new and the distributor cap and spark plug wires look OK.

The original 6 volt ignition coil fell apart some years ago and I fitted an old 12 volt coil that I had laying around. I used to have an adjustable resistor in the wire feeding the coil, but now I just feed 12 volts straight into it. Is it possible that the full voltage is too much?

Another odd thing - one time I ran out of gas and put a couple of gallons of 2 cycle chainsaw fuel mix in the tractor , and it ran like a champ!

Is it possible that my old tractor just won't run on the new type gasoline ?

Your tractor will run just fine on today's gasoline. The carburetor is still dirty. It needs cleaned again and adjusted to factory initial settings. A full ignition tune-up would also be in order.

notjustair · Feb 8, 2015

If your adjustments don't phase it one way or another it is still
clogged. With what it sounds like, it may be rust in there
causing issues not a true trash plug up. I've been working on
carbs for a lot of years and it is still a miracle if I get it fixed on
the first go around, likely that I will get it done on the second,
occasional that it takes a third try, and if I need to pull it apart a
fourth time I just bang on everything that's in there. It happens.
Just because you did it three times doesn't mean you caught
it.

Lay a feed sack on the work bench and tear it apart again. Use
an entire can of cleaner on ever nook and cranny (I didn't have
carb cleaner the last time so I used ether and it worked VERY
well). I just did my chore pickup last week and it took two tries.
The only thing I can get in one try is the old down draft Holley
on the grain truck, but she and I have been dancing for years.

rustred · Feb 8, 2015

your outlet in the tank going to sediment bowl most likely is the case of that. the stand pipe piece on the sediment bowl is partly plugged.
I have experienced this on my 1550 cockshutt. it sat for about 20 years and the tank got rusty. had the tank off a couple times and cleaned the best I could. it was good for a bit each time but eventually more rust would get into the outlet pipe. I fixed the problem this summer. I drilled out the stand pipe to fit a piece of 3/8 copper line. I then pushed in a piece of 1 1/2" of copper line into it and this fixed the problem. I baled round bales with the tractor this fall and she was working hard and no shortage of fuel. just have to remember that tank empty level is raised that much. the other option was to coat the tank but thought I would try my fix first.

old · Feb 8, 2015

Did you use a piece of wire or other such thing to poke out all the carb passageways?? If did not do so then that is why the carb is still causing problems

Oregon Tractor Jack · Feb 8, 2015

Your carb is still plugged. I rebuilt an H that was stuck an hadn't run in years. Went through the whole tractor. The carb gave me the most fits. Tractor would start but only run with the choke half way out. Took at least four tries to get it cleaned out. Go buy a tip cleaner for an OXYAcetylene torch. They have a bunch of stiff tip cleaners in really small sizes. They work well for all of those tiny holes in the carb. Lots of compressed air and carb cleaner. Once you think you have it clean, do it all over again.

Icuby · Feb 8, 2015

If I have to clean a carb,I use oven cleaner and let it soak a while. Works good for me.

David G · Feb 8, 2015

You can get corrosion in some of the passages that cleaner will never get out, thus the tip cleaners.

L.Fure · Feb 9, 2015

I wonder if anyone has tried to use a ultrasonic cleaner to clean out carburetors? A lot of watchmakers use them to clean watch parts. I have two in my watch repair shop that I use on watch parts. The ultrasonic action cleans very thoroughly.

rustyfarmall · Feb 9, 2015

I have an electric hotplate in the shop. Set a good sized pot on it, add enough water to immerse the carb parts, add a touch of laundry detergent, and just let it boil for awhile. It won't completely remove the crud, but it does take the "gooey" out of the crud. The residue still in the tiny passages will then come out fairly easily with aerosol carb cleaner and compressed air.

jsfarmall · Feb 9, 2015

As goofy as this will sound my cub was
doing the same thing. I tried everything
and finally changed the coil (if you have
coil type ignition). Cleared up and ran
beautifully. Not a typical coil
malfunction but I noticed the coil was hot
when I ran it but would always start
really easy and up to half throttle was
great. Above that was terrible.

john4689 · Feb 9, 2015

That is interesting about the coil. I have not checked it lately, but my coil used to get really hot. I was concerned that it might burst from the heat, but it never did.

Some years ago I had a rheostat (variable resistor) connected to the input side of the coil and ,now that you mention it, I do recall that the engine did not run well with the full 12 volts supplied to the coil. I forget why I took it off.

I have a new coil and resistor on order.

There is some new dirt (rust) in the fuel sediment bowl that I had not noticed before, so I ordered a sediment bowl gasket , so I can clean that out.

The float valve is leaking now, so it looks like I will be taking the carburetor apart AGAIN for the fourth time!

I still have a week to fix this before it goes to auction!

john4689 · Feb 14, 2015

I got it fixed! It was the ignition coil. The old one was bulged on the bottom and cracked at the top. I installed a new coil and hooked it up properly with a resistor so that it gets full voltage only when the starter motor is cranking and a diode so that the current does not back feed from the coil to the starter.

The only problem was when I removed and re-installed the starter cable, the 3/8 inch stud spun in place and twisted off the field winding connection inside the starter.

I tried to repair it by silver brazing an extension to the copper winding and bringing it out through the hole in the starter body.

The starter repair did not work. I am not sure what went wrong, I used some fiberglass sleeving and brush on electrical tape.
I must have pinched something when it went back together. I did not have any more time to fool with it so I ran out and bought a rebuilt starter.

I am still amazed by the fact that the tractor is 75 years old and my dealer (Messick Farm Equipment, Elizabethtown PA) had the starter in stock!
The price was reasonable, I could have bought one on ebay for a little bit less but it was worth it to me to have it right away.

H bad fuel

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