HELP!!
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=122777
Printed Date: 29 Aug 2025 at 7:06am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: HELP!!
Posted By: BenGiBoy
Subject: HELP!!
Date Posted: 02 May 2016 at 4:48pm
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At the end of last year my ('39) B started running 'off'. I pulled the head and found that the top compression ring on the 3rd. cylinder was broken. So in goes a new set of rings, thinking 'this will solve the problem', but no, it didn't. It runs better, but not right. It starts hard, sounds like it is missing on 1 or 2 cylinders (maybe?) I tried adjusting the timing, but it didn't change anything. Also, it idles up and down by itself. Anyone know what it's metter is? Could it be the coil? (it has a distributor on it.) ------------- '39 Model B Tractors are cheaper than girls, remember that! |
Replies:
Posted By: bluewavecaptain
Date Posted: 02 May 2016 at 4:57pm
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Check your compression. Maybe the valve lash needs adjustment? ------------- Charles(Two Rivers,WI) |
Posted By: Leon n/c AR.
Date Posted: 02 May 2016 at 8:16pm
| Did you double check that you had plug wires in correct order. Also have you checked dist. shaft. Leon |
Posted By: Ted in NE-OH
Date Posted: 02 May 2016 at 8:32pm
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Check spark plug wire locations. Firing order is 1-2-4-3. It is easy to mix up 3 and 4. ------------- CA, WD, C, 3 Bs, 2 Gs, WC, I-400, 914 |
Posted By: BenGiBoy
Date Posted: 03 May 2016 at 7:15am
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When I took the plug wires off I marked them with a permanent marker as too witch cylinder they came off of, so I think that they are correct. Maybe I will try switching #'s 3 and 4 around and see if it runs better. That won't harm the engine, right? I will check the compression. @ Leon: What do you mean by check the distributor shaft? ------------- '39 Model B Tractors are cheaper than girls, remember that! |
Posted By: BenGiBoy
Date Posted: 03 May 2016 at 4:42pm
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I switched the plug wires for cylinders #3 and 4, and it ran a TON better! (Thank You, Ted and Leon) No idling up and down, it still 'pops' a tiny bit, but that might be caused by the valves needing adjusted? Also, it starts a little bit hard, but maybe that is also connected to the valves? The valves are supposed to be adjusted to .010, correct? ------------- '39 Model B Tractors are cheaper than girls, remember that! |
Posted By: Dmpaul89
Date Posted: 03 May 2016 at 5:03pm
| Put timing back where it was. dont worry about valves yet. your way ahead of yourself there. start simple. check fuel flow, maybe adjust mixture screw on carb if it has one. make sure points are clean not pitted (they can pitt fast if not set right). Your jumping straight to worst case scenarios |
Posted By: Ted in NE-OH
Date Posted: 03 May 2016 at 5:33pm
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.010 HOT. I do .012 cold ------------- CA, WD, C, 3 Bs, 2 Gs, WC, I-400, 914 |
Posted By: BenGiBoy
Date Posted: 04 May 2016 at 8:24am
The points are good. The reason I was wondering about the valve adjustment was because I took it all apart a little while ago. I did check the valves with a feeler gauge yesterday, and they all seemed pretty good. (.010, or just slightly above) So I don't think that they are the problem. I will try checking the fuel flow, and tweaking the carb a tad. ------------- '39 Model B Tractors are cheaper than girls, remember that! |
Dmpaul89 wrote:Posted By: Leon n/c AR.
Date Posted: 04 May 2016 at 12:15pm
| BenGiBoy I was referring to wear on dist. shaft or bushing. If it has any slack you can see the point gap change by pushing back and forth on the shaft. Leon |
Posted By: BenGiBoy
Date Posted: 04 May 2016 at 12:50pm
Okay, I will check that. Thanks. ------------- '39 Model B Tractors are cheaper than girls, remember that! |
Posted By: BenGiBoy
Date Posted: 04 May 2016 at 12:53pm
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Checked the fuel flow, it seemed fast enough to me. I disconnected the fuel line at the carburetor and opened the valve on the sediment bowl, and the line was pouring out as much fuel as could come out at once. (without pressurizing the system, I suppose). I will try adjusting the carb. this afternoon, probably. I'll keep you posted.  ------------- '39 Model B Tractors are cheaper than girls, remember that! |
Posted By: tadams(OH)
Date Posted: 04 May 2016 at 1:22pm
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It's a 39 B, does it have a distributor, have you taken the mag off and put a distributor on? |
Posted By: Dmpaul89
Date Posted: 04 May 2016 at 1:23pm
| Champion plugs? if so throw them in the garbage |
Posted By: BenGiBoy
Date Posted: 04 May 2016 at 1:36pm
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tadams; I bought it with the distributor on it. Dmpaul89; It has Autolite plugs. #295 if I am remembering right. ------------- '39 Model B Tractors are cheaper than girls, remember that! |