WD45 Carburetor
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=174733
Printed Date: 19 Aug 2025 at 3:37pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: WD45 Carburetor
Posted By: 79fordblake
Subject: WD45 Carburetor
Date Posted: 27 Sep 2020 at 3:11pm
| Hey guys haven't been on in awhile. I had the carb on my WD45 professionally rebuilt a few months back. Some of y'all may remember this engine was completely overhauled a couple years ago. Ever since the overhaul choke needed to be on a little to run smooth under a load. After having carb rebuilt it still runs the same. I have power valve all the way open and it doesn't black smoke any and needs choke under a load. I spent alot of money replacing things that made no difference and had very little run time on them. Cap, rotor, wires, coil, electronic ignition module. Checked for good flow from tank. Adjusted valves, checked timing with a light. Still needs choke slightly on to run good under load. I need to find another carb to try I guess and see what happens. Also checked for leaks at manifold. |
Replies:
Posted By: DrAllis
Date Posted: 27 Sep 2020 at 3:41pm
| Sounds like the main jet in the bottom of the bowl needs to be drilled out .002" so you can then overfuel it with the adjustable main jet and then dial it back down where you want it. Is the engine 1/8" overbore?? maybe requiring a bit more fuel ?? |
Posted By: 79fordblake
Date Posted: 27 Sep 2020 at 4:48pm
| I was wondering about that but haven't went through with it yet. NOS D17 7.25:1 pistons, D17 governor spring. |
Posted By: Bill_MN
Date Posted: 27 Sep 2020 at 7:10pm
|
Definitely need main jet drilled out. I rebuilt my WD with higher compression and it likes about 50% ethanol, had to drill out the main jet a couple sizes just to get in the ballpark. Get a set of small numbered drill bits and a pin vise and go up one size at a time until you can run with the load needle about halfway in, fine tune from there.
------------- 1951 WD #78283, 1918 Case 28x50 Thresher #76738, Case Centennial B 2x16 Plow |
Posted By: 79fordblake
Date Posted: 27 Sep 2020 at 7:15pm
| Thanks for the help guys. I'll pick up a set of numbered drill bits this week sometime. |
Posted By: Dusty MI
Date Posted: 28 Sep 2020 at 7:51am
|
I like to participate on tractor caravans with my D-10 series III. After having the valves ground, it would start out running fine in the morning, and then not run right the rest of the day. And have to be trailered for the rest of the day. A couple weeks later I got to look into it and found that the float in the carb was set too shallow. Starting out in the morning when it was cool it worked fine. But as the day got hot the gas expanded so there were fewer BTU's in the amount of gas in the carb. I adjusting the float so the carb held more gas, and it runs just fine now. I would think that it would be difficult to intentionally set a carb that way. Dusty ------------- 917 H, '48 G, '65 D-10 series III "Allis Express" |
Posted By: 79fordblake
Date Posted: 15 Nov 2020 at 1:43pm
| Sorry guys I forgot to come back and tell you what happened. Drilled the jet out a couple sizes. Runs great now. Took it to plow day this weekend and it ran great. |
Posted By: Dave(inMA)
Date Posted: 15 Nov 2020 at 9:35pm
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Great to hear that your issue is no more - and thanks for coming back to let us know what happened! ------------- WC, CA, D14, WD45 |
Posted By: Sugarmaker
Date Posted: 16 Nov 2020 at 7:50am
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I have never drilled out a carb. Thanks for the info, and glad it is working better too. Lets see the plowing pictures! Regards, Chris ------------- D17 1958 (NFE), WD45 1954 (NFE), WD 1952 (NFE), WD 1950 (WFE), Allis F-40 forklift, Allis CA, Allis D14, Ford Jubilee, Many IH Cub Cadets, 32 Ford Dump, 65 Comet. |
Posted By: Alberta Phil
Date Posted: 16 Nov 2020 at 10:14am
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I had the same issue with my WD45 engine after Steve @ B&B rebuilt my carb. Had to drill the main jet out a couple of hairs bigger and that solved the lean running issue. My fault--as I had neglected to tell him I was running a Vinson manifold and some other engine mods!! Runs just fine now. |
Posted By: 79fordblake
Date Posted: 25 Nov 2020 at 12:28pm
My wife took a few pictures and some videos. I had a great time. It's good to have the tractor running the way it should be. One of these days I'll get it finished(maybe)!! :)   
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Posted By: IBWD MIke
Date Posted: 25 Nov 2020 at 1:37pm
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Looks good, lots of fun to plow with! |
Posted By: Sugarmaker
Date Posted: 25 Nov 2020 at 1:40pm
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Blake, Thanks for the nice plowing pictures! You have been doing some sheet metal work to the 45. It is weighted up nice too! Regards, Chris ------------- D17 1958 (NFE), WD45 1954 (NFE), WD 1952 (NFE), WD 1950 (WFE), Allis F-40 forklift, Allis CA, Allis D14, Ford Jubilee, Many IH Cub Cadets, 32 Ford Dump, 65 Comet. |