Farmall 140 keeps searching . . . .

Johns140 · Jan 5, 2016

The engine on my Farmall 140, continually surges up and down, looking for a sweet spot. The higher I put the throttle, the harder it surges. If I pull the tractor hard, the engine will smooth out. The manual I have, said to adjust the screw on the bottom of the governor. That didn't change anything. I checked the linkage from the governor to the carburetor, and it appears to be adjusted OK. I put new points and plugs in it, Saturday. Nothing has helped. Do you have any suggestions on my next mode of attach ?
Thank you for any help you can give me.

PHPaul · Jan 5, 2016

Not familiar with the specifics of that model, but in general Farmall governors that do that are suffering from one or both of two issues: A worn or missing spring and/or slop in the various connections between the governor control lever (ie: throttle) and the carburetor butterfly linkage.

Trace the entire path and look for worn and sloppy connections.

Another source of surging can be a partially blocked passage in the carburetor itself. It doesn't take a very big speck of floating debris to randomly block a critical passage in the carb. If the governor inspection doesn't result in a fix, the next step would be to tear down the carb and give it a good thorough inspection and cleaning.

Finally, the older Farmalls usually used a piece of fine mesh screen in the bowl under the tank as the only fuel filter. Checking that for hole and/or installing a secondary inline fuel filter can eliminate problems related to fuel contamination. Flakes of crud from those old gas tanks are common.

The Fred · Jan 5, 2016

Yes a lean condition like Mr. Paul says.

Good luck, Fred

DJ54 · Jan 5, 2016

If adjusting that bolt under the Gov. housing didn't change anything, and it's still hunting, I'd suspect either the bumper springs are broken, or the governor spring itself has broken, or came unhooked. Here is a link to the Case/IH online parts store, that shows an exploded view of your governor.Official Case IH Online Parts Store and Case IH Catalog for Best Parts Search and Best Parts Look Up. Case IH Parts for Case IH Tractors, Case IH Combines, Case IH Tractors, Case IH Manuals, Case IH Parts

The most common items that go wrong with these governors is spring #5 in the parts list, and the thrust bearing, part #25. Normally, when the thrust bearing goes bad, it will only accelerate up to about 1/3 throttle. As long as you've adjusted the linkage from the rockshaft clevis connection to the carb. properly, I'd suspect spring #5 is the culprit. If you have a Case/IH dealer near, they have them, and price is $12.72.

Easiest way to get the cover off is to remove at least the fan shroud. Removing the hood may give you a little better view to work. I'm thinking 4 bolts to remove, after disconnecting the carb. linkage, then bump the cover with a dead blow hammer, or a decent sized rubber mallet. Should come off fairly easy, without messing up the gasket. Spring #5 will be in that cover.

Johns140 · Jan 11, 2016

DJ54 said:
If adjusting that bolt under the Gov. housing didn't change anything, and it's still hunting, I'd suspect either the bumper springs are broken, or the governor spring itself has broken, or came unhooked. Here is a link to the Case/IH online parts store, that shows an exploded view of your governor.Official Case IH Online Parts Store and Case IH Catalog for Best Parts Search and Best Parts Look Up. Case IH Parts for Case IH Tractors, Case IH Combines, Case IH Tractors, Case IH Manuals, Case IH Parts

The most common items that go wrong with these governors is spring #5 in the parts list, and the thrust bearing, part #25. Normally, when the thrust bearing goes bad, it will only accelerate up to about 1/3 throttle. As long as you've adjusted the linkage from the rockshaft clevis connection to the carb. properly, I'd suspect spring #5 is the culprit. If you have a Case/IH dealer near, they have them, and price is $12.72.

Easiest way to get the cover off is to remove at least the fan shroud. Removing the hood may give you a little better view to work. I'm thinking 4 bolts to remove, after disconnecting the carb. linkage, then bump the cover with a dead blow hammer, or a decent sized rubber mallet. Should come off fairly easy, without messing up the gasket. Spring #5 will be in that cover.

http://www.tractorbynet.com/forums/images/smilies/2/thumbsup.gif

That is some really good information. Thank you very much. I really appreciate the link to the manual.

Johns140 · Jan 11, 2016

I believe the poor Tractor had been neglected for some time before I got it. The oil bath air filter was rusted through and there were several holes in the bottom of the cup, allowing dust / dirt to be sucked up from there. The rubber hose from the air filter to the carburetor had a hole in it about twice the size of a pencil eraser. So, sucking dust / dirt from there, too. I think I will clean / rebuild the carburetor, before I do anything else. Thank you for you help. I really appreciate it.

DJ54 · Jan 11, 2016

Those cups can be bought pretty reasonable new, although aftermarket from $15.00, and up. Hose is just a piece of straight radiator hose that can be bought at any auto parts store that sells hose by the foot. I did a search for the cup part number on Google, and got a ton of hits. Prices vary widely. https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=352597R91&start=10

A good cleaning of the carb. is a good idea, maybe not necessary for the rebuild though. Do a thorough cleaning, removing all jets, and be sure sure to remove the discharge nozzle, and check to see the tiny cross drilled holes aren't plugged. Also remove the elbow going into the carb. where the fuel line attaches. There is a fine mesh screen on the inside, that is attached to the elbow, that us the last filtration in the line. If it has a hole, or is not there, they can be bought new for less than $10.00.

Unless the throttle shaft bushing's are worn enough to be sucking air, main jet boogered on the end from someone running it in too far, float has a hole/sinking, or float needle valve is distorted, more then likely, just a good cleaning will suffice. But, to each his own. If you're careful removing the bowl, the gasket will stay intact, and will seal back up.

Good luck, let us know how you get along.