New to me '39 B
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=206462
Printed Date: 29 Apr 2025 at 4:25pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: New to me '39 B
Posted By: Twinkie8907
Subject: New to me '39 B
Date Posted: 27 Apr 2025 at 2:25pm
  Hi everyone, My wife surprised me with a new tractor. Right off the bat I have some questions, I tried searching the forum for some insight into them but did not have any luck. I believe It's a 1939 model B from the serial number. I think it needs a carburetor, I'm guessing those arent cheap or easy to find because the one that is on it has been brazed. Any insight on where I could find a replacement would be appreciated. My reason for this diagnosis is it will start but sometimes backfires before it does, it will rev up but has almost no power. It has a 60" yanmar/cub cadet deck under it and I never did get the deck fully spinning, killed the tractor twice trying. It will drive in ALL gears and does NOT pop out, when in 2nd or 3rd the speed varies as in the engine is struggling with the load. The other problem is the throttle linkage does not work correctly. It will throttle down but the lever wont make it throttle up, I have to get off and move the linkage by the carb manually. Wont lie havemt spent much time on this....I was till the engine fan tried to remove my finger(I'm fine, Pride hurt the most). I'm thinking I'm missing a spring. Thanks in advance, I might upload some more pictures if I can get it figured out. |
Replies:
Posted By: Twinkie8907
Date Posted: 27 Apr 2025 at 2:28pm
 Carb in question |
Posted By: steve(ill)
Date Posted: 27 Apr 2025 at 6:24pm
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front wheel / rims look like a 39... but has several "up grades" like the dish seat, alternator, distributor... and maybe the starter.. the only SPRING on the throttle is on the top of the governor at the front right corner of the motor... Your THROTTLE lever, should pull back and you can see an arm on the governor pivot rod rotate as you move the throttle.... there is a cross arm that goes to the left side of the motor, behind the radiator... that is pinned to the carburetor rod.. With motor off, push the throttle lever all the way forward, see that the governor arm PIVOTS and moves easily and the cross arm moves behind the radiator.. It should PULL the carburetor rod and open the carb lever to FULL FORWARD (open)... look where the problem is... what is not moving......... you can pull the pin at front left corner of motor and disconnect the governor cross arm from the carb rod... might be easier to tell what is moving and what is NOT at that point. ------------- Like them all, but love the "B"s. |
Posted By: steve(ill)
Date Posted: 27 Apr 2025 at 6:28pm
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here are a couple photos that show the linkage... https://www.allischalmers.com/forum/b-gov-surge_topic29781.html" rel="nofollow - https://www.allischalmers.com/forum/b-gov-surge_topic29781.html ------------- Like them all, but love the "B"s. |
Posted By: Twinkie8907
Date Posted: 27 Apr 2025 at 7:39pm
| Thank you for the info. Guessing im going to have to f8nd a used carb somewhere and have it rebuilt or rebuild it myself. As far as the "year" and upgrades the SN is B23207, which shows mid to late '39 according to Tractordata.com(yes I know not always accurate). It's possible it has a different transmission/rear end. It also have the foot brake kit in place of the original hand brakes(perhaps the reason for the seat?). I want one of those bigger bench style seat that has the backrest, I wonder if the brake linkages would clear, if not id imagine thats why it has this seat. 🤔 |
Posted By: steve(ill)
Date Posted: 27 Apr 2025 at 8:12pm
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your front wheels and transmission are from the 1939 model.. Someone could have added foot brakes to the unit. That happened often.. The BENCH seat will fit with foot brakes no problem. Many came that way for years. Someone added the bucket seat, they never came that way.. Original was a Magneto.. so the distributor and coil have been added or engine was changed. There is a sn on the engine also... early was on the top rear of the block where it bolts to the bell housing... Later the sn was on the flange on left side by bell housing. Most carbs can be rebuilt with a new gasket set... Dont hurt to open it up and look. ------------- Like them all, but love the "B"s. |
Posted By: jvin248
Date Posted: 27 Apr 2025 at 10:08pm
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. If it had ethanol fuel put in it last you'll have a gummed up carb and possible rust. Most have a screen where the inlet tube is that gets plugged with debris. Float, needle, seat check. I've successfully used the harbor freight small ultrasonic cleaner on several carbs. I split them and lay open side down. Dawn dish soap and green/purple/orange cleaner and warm water. That can save buying a carb kit. Use recreational fuel the last tank in the fall before storing. Those fuel stabilizers don't work. . |
Posted By: Twinkie8907
Date Posted: 28 Apr 2025 at 5:23am
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Thx for the info guys! That thread that Steve shared was especially helpful. From the pictures in that thread I think I diagnosed my linkage issue. The piece on top the govenor that has the spring attached to it is no longer attached to the rest of the linkage underneath it. I will try to post a picture after work today to make sure this is the problem. Thanks again for all the help. As for the carb, it has been brazed at the fuel inlet, then someone stacked silver solder on top of the braze(second post blow the picture up)...I'm afraid if I try to take it apart it may never work again. |
Posted By: steve(ill)
Date Posted: 28 Apr 2025 at 1:07pm
yea... that "lever and governor arm" above the governor is two pieces... connected by a spring.. both parts have to pivot easily ... spring ties them together.. ------------- Like them all, but love the "B"s. |
Posted By: Straanger
Date Posted: 28 Apr 2025 at 1:45pm
| That’s a good woman!!!!! Make sure you keep her happy! There will be a line waiting for her if she ever kicks you to the curb. |
Posted By: Twinkie8907
Date Posted: 28 Apr 2025 at 2:23pm
| Ya the line formed awhile ago. Long wait lol |
Posted By: steve(ill)
Date Posted: 28 Apr 2025 at 3:49pm
|
ii would not give up on the carburetor just yet.. If it does not leak externally, and does not flood / overflow... you might be OK.. Sounds like 90% of your problem is the linkage and governor operation.. Get all that figured out first... You might take the carb apart LATER and clean out the jets, trash laying in the bowl, etc.... Sometimes just a set of gaskets can help seal things up... If the inlet has been brazed, then dont take that apart.. just leav that screwed / brazed in the hole and work around it... and your right.. THEY ARE EXPENSIVE ! A carb off a B, C, CA will all fit if it comes to that. ------------- Like them all, but love the "B"s. |
Posted By: ekjdm14
Date Posted: 29 Apr 2025 at 4:48am
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Definitely don't trash the carb if it's not leaking from the repair, if there's still run issues after sorting the governor then as said a good clean and new gasket set can make a world of difference. Mine's running the best it's ever done with a new gasket kit in place, even after I managed to break the emulsion tube & solder it back together. Note-: if/when you do go through the carb, do NOT overtighten the emulsion tube (hollow hex fitting inside the throat of the carb) just nip it up against the new fiber washer! ------------- Stuck Farmer |
Posted By: Twinkie8907
Date Posted: 29 Apr 2025 at 3:00pm
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It does not leak when its running. In fact I wouldnt say it leaks, I would say it seeps. After I have run it(opened the valve at the sediment bowl) the carb will look wet where the braze/solder is. The sediment bowl is never empty so it cant "leak" or seep too much right? If I can get it running like a top with the linkage issue fixed I wont trash the carb. I dont want to take anything apart until I buy manual. I think the linkage problem is the top arm with the spring is very hard to turn. Seems to be what is binding the process up, however i have not disconnected any linkages yet to confirm this. Thanks again for the comments, intrest and most of all the knowledge. |
Posted By: steve(ill)
Date Posted: 29 Apr 2025 at 3:55pm
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that LONG GOVERNOR arm goes down into the case and pushes on the weight / gear mechanism... It sould be FREE to move, but it dont move much... on the LEFT side of the engine where the arm is connected to the carburetor rod, it moves maybe 1.5 - 2 inches and VERY FREE..... the LEVER on top of the Governor housing rotates on the PIN and it should be free.. you can pull it off and grease the pin if needed... and you NEED a spring to make things work.. You may or may not have the small oil tube on top of the LEVER / PIN.. every early models did not have that lube line. ------------- Like them all, but love the "B"s. |
Posted By: Twinkie8907
Date Posted: 29 Apr 2025 at 4:18pm
I can see grease on the one that does NOT move easy which is the one with the spring. I'm betting this is where the problem is, tho the linkage on the left side of the engine that moves 1-2" does have a decent amount of slop in the joint. It might be a culmination of a bunch of issues creating my main issue. I'm ordering a set of manuals from peaceful creek on Ebay, hope to use those and the knowledge base here to get it going good. I really want to mow my yard with it....if it wasnt raining I'd be changing the deck belt with one of the new ones I just got. |
steve(ill) wrote: