Farmall m

[rkbenish]

My m has all new parts from the gas
tank to the carburetor and it still
can't get to high rpm's. It only runs
when fully choked and when idled up it
dies.

 

[notjustair]

You spent cash on parts and still have a dirty carb. They aren't rocket science. Carefully take it apart and REALLY CLEAN every passage nook and cranny. I usually can crack them apart 3-4 times before I need a gasket set. I have an M I grind with that has a cracked bowl. It won't hold fuel long term, but it's clean so it runs like a top.

 

[pinball]

When you pull the choke out you are creating more of a vacuum on your carb. Either it needs that to be able to pull more fuel in or you have to much air leaking into the carb or a intake manifold leak. Carb kits are expensive any more. Most people don't know how or have the equipment to properly clean out a carb. I bought a new zenith carb for my 900 ford several years ago after fighting with the original carb. Best thing I ever did. 60 year old carb and you think it will work perfect. Proper cleaning and replace all parts in the carb and maybe youll get close. Very sensitive item on your tractor. Just my 3 cents worth.

 

[the tractor vet]

Yep dirty carb. It takes more then a spary can of carb and choke cleaner to do the job and a quick shot of compessed air . They need to soak in real carb cleaner the stuff that will remover your hide to the bone kind of stuff , then each tiny passage way needs cleand with the propper size drill bit . And when you think you have it cleaned out do it again . Remember they have had over seventy years to get grudded up and a hald hour of cleaning ain't getting the job done .

 

[Ted in NE-OH]

Could be any cause of gas restriction such as crud in gas tank.

 

[jon f mn]

Try a new coil, this sounds just like a bad coil. Could also be the condenser as both will do this when bad.

 

[Gary Mitchell]

That sounds just like an intake manifold gasket leak I once had on an M. gm

 

[teddy52food]

I had one in the neighborhood that idled rough even after cleaning the carb. After it went through a shed fire & got good & hot It was cleaned again & then it was right. Must have been some crud in it that cleaner didn't dissolve but heat burned it out.

 

[Oregon Tractor Jack]

Had the same problem with an H I rebuilt. The only way it would run is with the choke pulled out. Dirt in the carb was the problem. I had to take it apart three times and work on all of the little ports and holes to get it cleaned. I used the tip cleaner from my torch to clean out the holes. There are a bunch of small diameter rods that are stiff enought to push any crud out of the holes.

 

[504]

A couple of carburetor rebuild tools that most people don t use or know where to find is Steel Wool OOOO,and the drill bits and hand drill are cheep. Any welding store should have the hand drill tip cleaners for $6.00 or less.
The brass pieces will polish up like new, and will show you the tiny holes you did not even know they were there. A can of carburetor cleaner from an auto parts store will set you back $20.00,and will keep for reuse for years. (come in a gallon can with a small parts rack inside)

 

[David G]

If you had the carb apart, you sure the venturi did not fall out.

 

[rkbenish]

Is am going to get a rebuild kit. The most advanced kit I can find is for a super m, MV, and ect. Would that work for a m? The kits look identical and the ones specified for the m don't have the flaps.

 

[John B.]

It sounds like you're getting enough fuel to the carb if it runs when choked. You either have a vacuum leak between the carb and engine or clogged a jet in your carburetor. Those carbs have 4 circuits inside them. An Idle Circuit, High Speed Circuit, Float Circuit & a Choke Circuit.