CA surging
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=15310
Printed Date: 04 Feb 2025 at 6:50am
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Topic: CA surging
Posted By: Lance/SC
Subject: CA surging
Date Posted: 17 Jul 2010 at 7:59am
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I started my CA the first time in over a year yesterday and it was surging pretty badly. It didn't have a surge spring when I got it and when I put the new intake on I put a spring on. Now I am wondering if I should have added the spring. It is a 1955. Did all the CA's have surge springs? I am going out and pull out the old gas and add fresh and crank it and let it run for a while to see if it gets better.
Suggestions appreciated......Thanks
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Replies:
Posted By: CTuckerNWIL
Date Posted: 17 Jul 2010 at 8:15am
All that spring does is take slop out of the linkage. There can be other places in the governor set up that allows slop, which can cause the surge.
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Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF
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Posted By: Brian Jasper co. Ia
Date Posted: 17 Jul 2010 at 8:19am
To the best of my knowledge, all of the 125 engines have the surge spring. My CA has one and it will surge quite badly with the spring off. The spring is supposed to hook around one of the manifold studs close to the air cleaner. Dumping old gas is a good idea. I always put Stabil in my gas tractors. Unless they go on a ride, a full tank tends to last more than a year.
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"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
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Posted By: Lance/SC
Date Posted: 17 Jul 2010 at 10:31am
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OK, I got the gas changed, fired it up and ran it for about 15 minutes. The only way it will run is with the choke all the way out and about 2/3 throttle. It was showing about 19 lbs of oil pressure. Still surges badly.
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Posted By: CTuckerNWIL
Date Posted: 17 Jul 2010 at 10:43am
If you have to choke it to keep it running, you have a fuel restriction somewhere. Maybe crud plugging the supply line,restriction in the bottom of the tank or something plugging your carb up. I would address the running lean problem before worrying about the surging.
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Lena 1935 WC12xxx, Willie 1951 CA6xx Dad bought new, 1954WD45 PS, 1960 D17 NF
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Posted By: firebrick43
Date Posted: 17 Jul 2010 at 11:03am
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My CA surges with the surgue spring so it doesn't have it? But I agree, its a plugged jet or fuel line or fuel strainer, even possibly something blocking the fuel intake pipe in the tank itself.
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Posted By: Brian Jasper co. Ia
Date Posted: 17 Jul 2010 at 12:23pm
Having to keep the choke on to run says carb rebuild time to me.
BTW, 19 lbs of oil pressure is very good.
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"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
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Posted By: GregLawlerMinn
Date Posted: 17 Jul 2010 at 8:21pm
An improperly adjusted govenor rod will cause a lot of surging. To adjust properly, disconnect the govenor rod from the throttle rod (behind the fan on the left side); with engine off, move the throttle to wide open position; then manually pull the throttle rod to wide open position; you should be 1/16" to 1/8" short of re-engaging the govenor rod to the throtlle rod. Bend the govenor rod as necessary to obtain the correct gap. When installing the anti-surge spring hook the small end to the throttle arm and the large end over the top manifold stud just forward of the lower end.
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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
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Posted By: Dave(inMA)
Date Posted: 17 Jul 2010 at 8:31pm
Greg - thanks for posting a great description of this process. Someone posted a few days ago saying that the anti-surge spring is connected to the CHOKE rod...... I was pretty sure that was not right - both you and the parts manual confirm it!
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WC, CA, D14, WD45
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Posted By: TMiller/NC
Date Posted: 17 Jul 2010 at 8:44pm
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Lance, are you planning attending the Arden, NC show in Oct. this year? I hope Joseph and I will be there as spectators, it is too much uphill from here to take an AC. Let me know if you are, and we will try to meet up some where. Tim
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Posted By: Lance/SC
Date Posted: 18 Jul 2010 at 7:56am
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My wife wants to go back so I guess that answers your question, huh? LOL Will probably go up on Friday morning and visit my brother in Marshall and hit the show early on Saturday.
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Posted By: Gerald J.
Date Posted: 18 Jul 2010 at 8:21am
Surging can come from improper carburator tuning. Its not present like the "modern" briggs carb. It can surge because it can't run on the idle mix so slows down and governor yanks the throttle open which fires up the acceleration pump and the power jet. Then it goes to fast and the governor closes the throttle, to repeat. So to cure that you have to make it run well at idle with the governor overridden. E.g. don't let the governor open the throttle, just hold it closed against the idle speed adjust screw and adjust the idle mix screw (usually opens to add air and lean the mixture) for maximum idling speed. Then run it fast still trying to override the governor and adjust the power screw for the fastest speed. Or better hitch a plow that's one size too big and pull it down from what the governor can control and adjust the power screw for maximum speed which will be on the rich side of economy. The adjust the idle screw and repeat the cycle a couple times. They do interact.
Alternatively you can let the governor work and watch for the governor to close the throttle as you optimize the idle mix and the power screws while idling and running fast but that can be more subtle. You can't ignore the governor, it will hide changes in those adjustments.
Gerald J.
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Posted By: Dick L
Date Posted: 18 Jul 2010 at 12:51pm
Gonna have to hunt a long time to find an acceleration pump in a carburetor on a CA. Might be a life time hobby.
Idle speed (RPM's) is set by the butterfly stop screw. The engine running smooth at idle is set by adjusting the (idle) mixture screw. After the idle is set and running smooth any readjustment to this idle screw will alter the smooth running at idle.
Adjusting the governor cross over arm at wide open works however it works the same at idle as both arms are the same length. To keep the engine from surging the governor must hold the butterfly closed with a slight pressure at idle. 1/16" is good but they will work at dead nuts. it will surge if you adjust the cross over arm 1/16" the wrong direction. That is the reason I suggest you adjust the cross over arm at idle taking into account the reason for the 1/6" misalignment of the connection. Easier to get it correct if you understand the reason for doing it.
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