CA Still surging
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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=48124
Printed Date: 27 Aug 2025 at 4:11pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: CA Still surging
Posted By: Austin(WI)
Subject: CA Still surging
Date Posted: 29 Mar 2012 at 9:36am
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Can't remember if I posted an update posting, but I tried to detect the reasons for my CA's surging. I sprayed brake clean around the manifold and carb, and there are no leaks. What could be the next possiblity? It's not the gas tank, fuel bowl, fuel line, or carb...what could it be? ------------- "Better By Design" |
Replies:
Posted By: Redwood
Date Posted: 29 Mar 2012 at 10:00am
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You seem to have covered the obvious stuff.
As the problem seems simple enough there can only be a few possibilities. as that typically a surge would be an increase in fuel mixture or the richness of the mixture. it would seem that you ether overlooked somthing (worth a second look at the carb) or you might consider that you don't have surge as such but a lag. the fuel going in is only burning properly when the engine appears surged and not running right when it reving lower.
Just a thought, I'm not an expert but, my next step would be to double check the obvious and easy to see if I missed somthing then go after the timing/firing/chamber(fouling and such)
Hope you find a simple solution...
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Posted By: Dick L
Date Posted: 29 Mar 2012 at 10:00am
| Are you sure that the cross over arm is set right? |
Posted By: Redwood
Date Posted: 29 Mar 2012 at 10:34am
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Just another thought as it runs through my mind. If...that is if you can't find a solution. If it is loading and freeing up, in neutral. You can pull the plugs and turn it by hand you should be able to see if you have a bad bearing or other binding issues.
I don't think this is it, from your description, but on an off chance it's an easy thing to check to eliminate and a bad thing not to check. when it is running a mechanic's stethiscope would also help to eliminate that as a problem as you should hear the irregularities.
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Posted By: EdK
Date Posted: 29 Mar 2012 at 10:35am
| Not sure if it's on a CA, but my C has an anti surge spring connected to the carb arm. |
Posted By: GregLawlerMinn
Date Posted: 29 Mar 2012 at 1:34pm
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Follow-up th Dick L's question.Verify that the govenor rod-throttle rod has correct clearance. Remove the cotter pin from the throttle shaft (left side of engine, just above the gennie). Move the throttle control to the wide open position then pull the (now loose) throttle rod towards the govenor rod. You should be 1/16-1/8" short of re-engaging the two. If not, bend the govenor shaft until you get this clearance. Surging can also be caused by a missing, or improperly installed, anti-surge spring on the throttle rod. The spring should be installed thru the hole in the throttle shaft (just ahead of the carb), small enf of spring thru shaft; the large loop goes over the top manifold stud just ahead of the carb (a piece of bent heavy wire is helpful in pulling the large loop over the stud). ------------- What this country needs is more unemployed politicians-and lawyers. Currently have: 1 D14 and a D15S2. With new owners: 2Bs,9CAs,1WD,2 D12s,5D14s,3D15S2s, 2D17SIVs,D17D,1D19D;1 Unstyled WC |
Posted By: Brian Jasper co. Ia
Date Posted: 29 Mar 2012 at 4:37pm
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+2 on making sure the governor arm is right. You want the throttle arm on the carb to be the limit on wide open throttle, not the governor or it's linkage. If you're needing some choke to run smoothly, it's too lean. Sounds like you have a fixed main jet carb. No vacuum leaks, then you either have a restriction in the carb, low float level, or you have leaky valves/rings in the engine. ------------- "Any man who thinks he can be happy and prosperous by letting the government take care of him better take a closer look at the American Indian." Henry Ford |
Posted By: WEL(IN&TN)
Date Posted: 29 Mar 2012 at 6:46pm
| Sounds like the anti-surge spring is missing. It attaches to the govenor rod in a tiny hole (just behind the carb) to a manifold stud. |
Posted By: Austin(WI)
Date Posted: 29 Mar 2012 at 7:42pm
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I have the spring...but it still surges. The tractor smells wierd when you run it wide open without the choke, and that is when it surges. ------------- "Better By Design" |
Posted By: norm[ind]
Date Posted: 29 Mar 2012 at 7:48pm
| shortage on fuel does it smooth out with the choke have also seen it in the carb adjustments my 2 cents shows the gov is working o.k. |
Posted By: Dick L
Date Posted: 29 Mar 2012 at 9:27pm
When I was pulling where they checked the RPM's I would bend the cross over arm to make it surge so the couldn't get an rpm check. (Aint no way a tractor running like that can be competition. Let him pull.)  I bent the arm to where as soon as the tractor started to pull down the surge stopped. I do not have a surge spring on my engines of that type and I don't have a surge problem if I don't want to have some surge. I think when he gets the problem solved it will be the proper adjustment of the cross over arm. You do also have to have the carburetor adjust properly also. |
Posted By: Austin(WI)
Date Posted: 30 Mar 2012 at 8:02am
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I have checked the timing and and adjusted the valves. What is it about carb rod and gov rod that needs to be adjusted? The choke has to be half closed to run smooth. ------------- "Better By Design" |
Posted By: Gerald J.
Date Posted: 30 Mar 2012 at 10:50am
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Choke half closed says its running lean. Too much air for the idle screw. Float level with too little gas in the float bowl, or main jet closed (if adjustable or crudded up) too much. Having a rich enough idle with low float level or a lean power just is a classic cause of surging. Engine slows, governor opens the throttle until it speeds up, then shuts the throttle because it sped up. Gerald J. |
Posted By: Austin(WI)
Date Posted: 30 Mar 2012 at 11:58am
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So maybe I should take the carb off and clean it out again. The float and the needle and seat are brand new. ------------- "Better By Design" |
Posted By: WC7610
Date Posted: 31 Mar 2012 at 9:05pm
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Listen to Dick, I had the same problem with my B and bent the cross arm like he said and Bingo, took care of it. ------------- Thanks Most Bad Government has grown out of Too Much Government- Thomas Jefferson |
Posted By: Steve in NJ
Date Posted: 31 Mar 2012 at 10:39pm
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I don't know, but it sounds to me like its to lean up top. You said it only surges at full throttle. When you pull the choke patially closed, the surge goes away. When you pulled the choke partially closed, you fattened up the mix. You may have dirt and debris in the enrichment circuit of the carburetor which is causing a lean condition at high speed. You need to do more than just take the carb off and clean the bowl area. You need to blow compressed air through the passages in the carb and clean em' out. Also run a thin wire through those passage ways to dislodge anything that might be in there... HTH
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