D12 Series 3 issue
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=149378
Printed Date: 29 May 2025 at 5:01pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: D12 Series 3 issue
Posted By: irlbeck A-C'S
Subject: D12 Series 3 issue
Date Posted: 11 Apr 2018 at 7:15pm
When I started the tractor it went full throttle. I shut off the engine. While I was checking linkages I found that the throttle shaft was able to pull out of the side of the carb. This is what I found. The heads of the screws sheared off.   Throtttle plate is gone. I pulled the manifold and could not locate it. Looks like I'll be pulling the head off.  ------------- B,C,CA,(2)WC's,(4)WD's,(2) WD45'S, 45Diesel, (2)D12'S Series 2, D12 Hiclear,(2)D12 Series 3, HD3, D17NF (3)D17 Series 4 Diesels, M-100 Grader,8550,A few Lawn tractors lots of other AC stuff |
Replies:
Posted By: Hubert (Ga)engine7
Date Posted: 11 Apr 2018 at 7:45pm
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Pulling the head is a smart move. Try to find the two screw heads while you are in there also. Let us know how far in everything went. ------------- Just an old country boy saved by the grace of God. |
Posted By: PaulB
Date Posted: 12 Apr 2018 at 12:10am
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The heads of the screws have most likely blown away into oblivion. You may or may not find the butterfly. ------------- If it was fun to pull in LOW gear, I could have a John Deere. Real pullers don't have speed limits. If you can't make it GO... make it SHINY |
Posted By: johnkc
Date Posted: 12 Apr 2018 at 12:19am
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That can make guy say Dammit ------------- I support the development of hybrid automobiles and alternative fuels as I need DIESEL fuel for my ALLIS CHALMERS! |
Posted By: corbinstein
Date Posted: 12 Apr 2018 at 6:25am
| first place I would check is the manifold and the top of the intake valve to see if it's stuck there. |
Posted By: DiyDave
Date Posted: 12 Apr 2018 at 6:44am
| I'd pull the manifold, and see if its up there, somewhere... |
Posted By: JayIN
Date Posted: 12 Apr 2018 at 6:58am
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I dropped 1 tiny carb screw into a F250 motor and it grenaded the piston. Good luck! ------------- sometimes I walk out to my shop and look around and think "Who's the idiot that owns this place?" |
Posted By: irlbeck A-C'S
Date Posted: 12 Apr 2018 at 3:50pm
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Couldn't find anything in the manifold or in the valves. I may try to run a scope in the spark plug holes this afternoon. Don't want to take a chance and mess something up so I'll be pulling the head. Going to need a head/manifold gasket set as well as a butterfly for the carb. at a minimum. Will probably order them now but may wait to see if I can pick them up from a vendor at the Goto in Gray. ------------- B,C,CA,(2)WC's,(4)WD's,(2) WD45'S, 45Diesel, (2)D12'S Series 2, D12 Hiclear,(2)D12 Series 3, HD3, D17NF (3)D17 Series 4 Diesels, M-100 Grader,8550,A few Lawn tractors lots of other AC stuff |
Posted By: HudCo
Date Posted: 12 Apr 2018 at 4:36pm
| might be a good time to get the head done before its wore right out anyway. or at least vaccuum test test the valves to see how well there seating |
Posted By: irlbeck A-C'S
Date Posted: 12 Apr 2018 at 8:46pm
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Pulled off the head. Found a tiny piece of brass in the #3 cylinder. Looks like it may be one of the screw heads. No sign of the butterfly. Everything looks good. No damage to anything. Just need to get a new butterfly and it will be back running soon. ------------- B,C,CA,(2)WC's,(4)WD's,(2) WD45'S, 45Diesel, (2)D12'S Series 2, D12 Hiclear,(2)D12 Series 3, HD3, D17NF (3)D17 Series 4 Diesels, M-100 Grader,8550,A few Lawn tractors lots of other AC stuff |