Farmall M Carburetor removal

spragi6

New User
Hey everyone,

First time posting on here. I just got a 1949 Farmall M that I don't believe has been cleaned or have had any maintenance done to it since it left the factory in 1949. I am in the process of overhauling multiple things on the tractor including the carburetor...but i am having issues disconnecting the throttle linkage between the carb and the governor. My shop manual says to just unbolt the carburetor, disconnect the tube from the carburetor that is protecting the linkage to the governor and then the linkage should pull right out of the carburetor (what i imagine to be a slip yolk type of design). But the linkage, in fact, does not pull right out. I have taken the plate with the copper vent tube off the governor to get a look at the governor end of the linkage, but i'd rather not pull that off for fear of having to re adjust the governor once i get it back running. Any input is appreciated
Thanks!
 
assuming you have throttle and choke wire loose. It should slip right out of governor linkage. Iusually losten the other end, on governor also. You will hae to adjust it when you put crarb back on to make sure it is moving freely anyway
 
Here is a before and after set of pics from my 400 carburetor
rebuild. Your M is designed just the same. There is no reason to have to loosen the governor tube, it will pivot at the governor end and allow you to pull the carb down from the studs. My carb was so dirty that the small stem that looks like key stock that contacts and moves the throttle (shiny part in the after pic) had worn down. Dirt and gunk was packed in there and it still ran!
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Here is the worn part I am talking about. The extended part is supposed to be as wide as the "key stock" on the barrel, which goes into the slot on the shiny part in my previous pic.
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The stem extending from the shiny throttle part on the carb goes into the hole on the end of the "barrel" of the governor rod. It should be a snug fit, not all rounded out and pitted like my old one. Again, this tractor ran when I bought it in this condition!
So it could be that your stem from the throttle and the hole in the governor rod are corroded together and won't pull apart.
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Something that hasn't been mentioned that I ran into on my H. Sometimes, the end of the throttle shaft (which slips into the enter hole on the governor linkage - NOT the tab that aligns with the notch) gets corroded just enough to create a bond between the two. A little patience, wiggling, twisting, and GENTLE prying with a screwdriver will get them apart.

Enclosed is a couple photos of the carb after I rebuilt it for my M (just for fun).
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Ken, nice looking rebuild! You also explained what I was expressing in much clearer terms. Hopefully spragi6 can now confidently remove his carb! Good Luck!
 
Thank you! I try to do my best... MY F20 carb was pretty bad though. It runs pretty good, but I think I have some idle circuit issues right now. It won't quite idle down - I am thinking the throttle shaft/economizer valve are sticking slightly above idle. I'll have to tear it down after the show in two weeks and take a look at it.

Also, My H has some rough spots, but overall it is good. I think it is in need of a good valve job, and head gasket as I am getting some bubbling to the outside near the #4 cylinder... Ah well.. All tractors run, and they run pretty well considering they have all been basket cases. (Photos of the H carb - finished product looks similar to the M carb I did).
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That is about the worst looking shaft I have ever seen. I just worked over a M carburetor and the hole in end was very badly work. I was able to use a dreml and get a nice enough hole to install a bushing made out of an old carburetor needle valve seat. Surprised myself and it fit nicely.

On another part of this subject, it is always a very good idea to loosen up the other end where that tube fastens to the governor because that is the last screws to tighten after tightening dow the carb and the tube at the carb. Improper alignment is the cause of a lot of poor governor operation and hunting of rpm's etc.
 
Pete23, Indeed it was a mess in the 400 carburetor ! And like I keep saying, the darn thing was running when I bought the tractor! This old girl must of sat in someone's grove for years before someone else pulled it out and got it running. There was water and rust in the tube but the governor(M & W)was clean as a whistle. I have only rebuilt two Farmall carbs in my life, the other being an M I just recently sold. I'm just a 57 year old farm kid with a passion and a set of tools. Been working for the Post Office for over 30 years now and I only got back into wrenching here in the past 2-3 years. My hobby over the previous twenty has been hunting deer with a bow which led to food plots which led to Farmall !!
 
Wow, thanks for all of the replies. Turns out, the key stock was corroded and stuck inside the throttle shaft. I ended up pulling the clevis pin out of the linkage at the governor and then just pulled the rod and carb out in one piece. Wasn't as corroded as Happyfeets', but just enough to make it stick.
 
I have a few other questions I hope you guys might be willing to answer seeing as your memory may be fresh with the rebuild still.

1. I have these pieces that came in my rebuild kit that I cant figure out what they go to. I'm assuming the cloth type piece on the right is the packing for the main jet adjusting needle and nut. I'm only guessing this because i pulled out an unknown material from the seat of the hole the needle screws in to that somewhat matches this.

2. What would you guess these assembly instructions are referring to on steps 8 and 9? I have no idea what the strainer screen assembly would be and the only part i removed in relation to the choke was the butterfly and butterfly shaft and the spring and ball assembly.

Thanks!

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The parts you have in your pic I believe are for the "weep hole" in the bottom of the bowl. The main jet packing was a graphite slug(think pencil lead) that took you some time to dig out unless you haven't done so. It's a pellet with a hole thru it for the needle to go thru. It puts pressure on the needle jet and holds it firmly in place. Depending on the kit you have purchased, you may or may not have total rebuild capability .The strainer screen is likely the gas line connection, a brass fitting with strainer screen attached to it. No offense, but your kit may have come from overseas and the translation of wording in the instructions may leave something to be desired. Best advice is to take your time and thoroughly clean out every orifice and don't be in a hurry! This old tractor has waited many years for you to rescue it. Do right by it!
 
No offense taken...I usually don't go the cheapo'/quick and dirty route, but I just wanted to get this thing running...lesson learned i suppose. The kit i bought definitely didn't come with all of the parts. Yeah it took me about a half hour to scrape all of that graphite out. I've got plenty of time into cleaning this thing already so i'm definitely taking me time and (trying) doing it right. Thanks for the feedback!
 
(quoted from post at 18:45:55 08/04/17) Woops.. There it is! I don't think I processed what you said quite as well as I should have - you stated it first! :)

Ken, what did you use to get that nice glossy black finish on the carbs?
 
(quoted from post at 17:31:49 08/05/17) The parts you have in your pic I believe are for the "weep hole" in the bottom of the bowl. The main jet packing was a graphite slug(think pencil lead) that took you some time to dig out unless you haven't done so. It's a pellet with a hole thru it for the needle to go thru. It puts pressure on the needle jet and holds it firmly in place. Depending on the kit you have purchased, you may or may not have total rebuild capability .The strainer screen is likely the gas line connection, a brass fitting with strainer screen attached to it. No offense, but your kit may have come from overseas and the translation of wording in the instructions may leave something to be desired. Best advice is to take your time and thoroughly clean out every orifice and don't be in a hurry! This old tractor has waited many years for you to rescue it. Do right by it!

Well I ended up getting the full IH rebuild kit and the closest thing i could see to that graphite slug for the needle jet seal is on the right in the picture, but its made out of a foam/cloth like material.
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Steiner has a premium carb kit that includes the packing pellet. Contact a Case/IH dealer and see if they can get you one. It's out there, you just have to find it!!
 
(quoted from post at 11:59:37 08/09/17) No offense taken...I usually don't go the cheapo'/quick and dirty route, but I just wanted to get this thing running...lesson learned i suppose. The kit i bought definitely didn't come with all of the parts. Yeah it took me about a half hour to scrape all of that graphite out. I've got plenty of time into cleaning this thing already so i'm definitely taking me time and (trying) doing it right. Thanks for the feedback!

There is a big difference in rebuild kits. Some of those parts shown in your picture are not even for your carburetor. They will not even fit where the instructions indicate. Also, more often than not, the original parts you remove are better than the new parts included in the kit. Don't be afraid to reuse the original parts after a thorough cleaning. You MIGHT be able to get the graphite packing from a Case-IH dealer. NOTHING else will work.
 

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