Super A running problem

Farmall Super A, AV, 100, 130, & 140 1939 - 1973

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Brly
Posts: 19
Joined: Thu May 14, 2015 6:13 pm
Zip Code: 17701

Super A running problem

Postby Brly » Sat Feb 13, 2016 8:01 pm

Hi Folks,
1951 Super A. I got it early last summer and had to replace the thrust bearing in the governor. Rewired it (it was already changed over to 12V), changed all the fluids and mowed my yard all summer with a 60" Pennington mower. Ran fine.
I put the plow and chains on (wheel weights were already on) and got ready for winter. We haven't had much snow, so I didn't run it much in the last few months.
A problem cropped up that last few times I've had it out. It starts, idles and revs up fine, but under load it will stumble and if I don't get on the clutch fast enough, it will eventually stall (2 or 3 seconds). So, I did some reading here and tried a few things today. I checked the fuel cap to make sure it's clear. I could blow air through it, so I assume that's enough. Touched up the points and reset the gap to .020". Put a new 12V, internal resistance coil on and new spark plug wires. The spark plugs are Autolite 3116 and they're only a couple months old.
Took it out for a test and there's no difference. I ran it long enough to make sure it was good and warmed up and then the test was to start from a stop in second gear. I found that the problem only occurs at full throttle. At half throttle, it will take off with no stumble.
To further describe what is happening, at full throttle I can take off in second gear if I let the clutch out very(!) slowly and it will run normal, but if I then drive uphill or otherwise put a load on the engine, it will stumble. Sometimes it will recover on it's own and continue to run, but it seems to be getting worse now and will stall if I don't get on the clutch.
I haven't checked the fuel flow yet to see if my fuel supply is clogged up somewhere. I also have not checked the compression yet. I tried pulling the choke when it would start to stumble, and that didn't help.
So, I'm at a loss here. Why will it run normal at half throttle and stumble at full throttle? I'm open to any ideas.
Thanks,
Ben

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TurboRoadster
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Re: Super A running problem

Postby TurboRoadster » Sat Feb 13, 2016 9:05 pm

clean the carb

staninlowerAL
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Tractors Owned: Cubs: (3)'49's, (1)'52, (1)'57 IH Cub LoBoy w/FH, (1)'72 154 Number Series Loboy, '76 Longstripe w/FH, Mowers: C-22, Bush Hog 412, Pennington 59, Woods RM42CF, Woods 42, assorted FCub plows, planters, discs, etc. OTHERS: '49 AC B & Ind. Sickle mower, '61 AC D12 Ser 2, '52 8N, '56 Ferguson 35 Deluxe, '53 MM BG (offset), (2) '49 Avery V's, '56 JD 420C, with Blade and fire plow, '85 JD 850 (Yanmar) w/72" belly mower, '76 Yanmar 1500, Sears Surburban's, MTD's, Jeeps & other misc. "treasures"
Location: AL (Southwest)

Re: Super A running problem

Postby staninlowerAL » Sat Feb 13, 2016 9:13 pm

TurboRoadster wrote:clean the carb

AND make sure there is an unobstructed fuel flow from the tank to the carb. Try catching about a quart at the carb drain point to make sure it flows freely. Any filters in the line or tank? Don't overlook the strainer/filter in the carb inlet (if it has not been removed already) and the fuel outlet shutoff valve. I would check those things first before opening up the carb. Stan

Brly
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Zip Code: 17701

Re: Super A running problem

Postby Brly » Sat Feb 13, 2016 10:44 pm

Thanks guys. No filter in the line.
I'll make sure everything is clear tomorrow morning.

Ben

staninlowerAL
5+ Years
5+ Years
Posts: 2664
Joined: Fri Oct 29, 2010 11:34 pm
Zip Code: 36558
Tractors Owned: Cubs: (3)'49's, (1)'52, (1)'57 IH Cub LoBoy w/FH, (1)'72 154 Number Series Loboy, '76 Longstripe w/FH, Mowers: C-22, Bush Hog 412, Pennington 59, Woods RM42CF, Woods 42, assorted FCub plows, planters, discs, etc. OTHERS: '49 AC B & Ind. Sickle mower, '61 AC D12 Ser 2, '52 8N, '56 Ferguson 35 Deluxe, '53 MM BG (offset), (2) '49 Avery V's, '56 JD 420C, with Blade and fire plow, '85 JD 850 (Yanmar) w/72" belly mower, '76 Yanmar 1500, Sears Surburban's, MTD's, Jeeps & other misc. "treasures"
Location: AL (Southwest)

Re: Super A running problem

Postby staninlowerAL » Sun Feb 14, 2016 12:00 am

filter1.jpg
If yours has not been removed the carb inlet screen should look like this.

Brly
Posts: 19
Joined: Thu May 14, 2015 6:13 pm
Zip Code: 17701

Re: Super A running problem

Postby Brly » Sun Feb 14, 2016 9:19 am

Took the carb off this morning. Had great fuel flow from the gas tank to the carb. Took the elbow out that you have pictured and that was clear, but I blew it out anyway. Cleaned the carb. Put it all back together and its running the same. One notch on the throttle is the difference between normal and stumble.
I can't guarantee that the carb is perfectly clean, but I ran copper wire through all of the passages and jets and then blew them out with a spray can of carb cleaner. That has worked for me in the past and it actually looked very clean inside.
Any other ideas?

Thanks,
Ben

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Re: Super A running problem

Postby Eugene » Sun Feb 14, 2016 9:32 am

Timing light. Check the ignition timing at low idle and again while you advance the throttle.
I have an excuse. CRS.

staninlowerAL
5+ Years
5+ Years
Posts: 2664
Joined: Fri Oct 29, 2010 11:34 pm
Zip Code: 36558
Tractors Owned: Cubs: (3)'49's, (1)'52, (1)'57 IH Cub LoBoy w/FH, (1)'72 154 Number Series Loboy, '76 Longstripe w/FH, Mowers: C-22, Bush Hog 412, Pennington 59, Woods RM42CF, Woods 42, assorted FCub plows, planters, discs, etc. OTHERS: '49 AC B & Ind. Sickle mower, '61 AC D12 Ser 2, '52 8N, '56 Ferguson 35 Deluxe, '53 MM BG (offset), (2) '49 Avery V's, '56 JD 420C, with Blade and fire plow, '85 JD 850 (Yanmar) w/72" belly mower, '76 Yanmar 1500, Sears Surburban's, MTD's, Jeeps & other misc. "treasures"
Location: AL (Southwest)

Re: Super A running problem

Postby staninlowerAL » Sun Feb 14, 2016 9:35 am

Have you checked all the throttle linkage from the carb to the governor for any loose connections? Wear in the linkage will sometimes do strange things to throttle response. BTW, could you post a picture of the Pennington mower? I'm planning on adding one to my 154. Thanks. :) Stan

Brly
Posts: 19
Joined: Thu May 14, 2015 6:13 pm
Zip Code: 17701

Re: Super A running problem

Postby Brly » Sun Feb 14, 2016 11:12 am

I have played with the timing just by turning the distributor and listening; don't have a light. No change to the stumbling problem when I retard or advance the ignition. I'm all ears if you have any other info on timing.
I will take a look at the linkages, but I would think that would be a consistent issue throughout the throttle range, not just at high throttle.
I even started fooling with the governor, but that didn't make any difference either. I made sure all the spark plugs were tight.
I'll have to dig out my compression tester and see what I have.
I just can't figure why it only happens at full throttle.
I really appreciate the help so far guys. Keep any ideas coming!

Here's the only picture I have of the Pennington mower. Got my wife to take it for a spin last summer.
Image

staninlowerAL
5+ Years
5+ Years
Posts: 2664
Joined: Fri Oct 29, 2010 11:34 pm
Zip Code: 36558
Tractors Owned: Cubs: (3)'49's, (1)'52, (1)'57 IH Cub LoBoy w/FH, (1)'72 154 Number Series Loboy, '76 Longstripe w/FH, Mowers: C-22, Bush Hog 412, Pennington 59, Woods RM42CF, Woods 42, assorted FCub plows, planters, discs, etc. OTHERS: '49 AC B & Ind. Sickle mower, '61 AC D12 Ser 2, '52 8N, '56 Ferguson 35 Deluxe, '53 MM BG (offset), (2) '49 Avery V's, '56 JD 420C, with Blade and fire plow, '85 JD 850 (Yanmar) w/72" belly mower, '76 Yanmar 1500, Sears Surburban's, MTD's, Jeeps & other misc. "treasures"
Location: AL (Southwest)

Re: Super A running problem

Postby staninlowerAL » Sun Feb 14, 2016 3:27 pm

Thanks for the photo. That's a good looking mowing combo, (helper also). The SA probably provides plenty of power for the 60 inch cut. Keep posting on what it takes to solve the problem. Stan

Brly
Posts: 19
Joined: Thu May 14, 2015 6:13 pm
Zip Code: 17701

Re: Super A running problem

Postby Brly » Sun Feb 14, 2016 7:16 pm

The 60" deck is no problem for the SA cutting yard grass. I haven't tried it on anything more than that, but I imagine it would do fine.
I kept at it today. It's a carb issue. I found that if I put the choke on very slightly, just enough that I could hear a difference in how it was running, it fixed the stumbling issue, even at full throttle.
This tractor has a Carter carb. The only adjustment is the air screw on the outside. Other than that, I would have to start swapping jets.
I'm hoping I can find a small air leak somewhere that's causing the slightly lean condition. Might be something with the float too?
Ben

staninlowerAL
5+ Years
5+ Years
Posts: 2664
Joined: Fri Oct 29, 2010 11:34 pm
Zip Code: 36558
Tractors Owned: Cubs: (3)'49's, (1)'52, (1)'57 IH Cub LoBoy w/FH, (1)'72 154 Number Series Loboy, '76 Longstripe w/FH, Mowers: C-22, Bush Hog 412, Pennington 59, Woods RM42CF, Woods 42, assorted FCub plows, planters, discs, etc. OTHERS: '49 AC B & Ind. Sickle mower, '61 AC D12 Ser 2, '52 8N, '56 Ferguson 35 Deluxe, '53 MM BG (offset), (2) '49 Avery V's, '56 JD 420C, with Blade and fire plow, '85 JD 850 (Yanmar) w/72" belly mower, '76 Yanmar 1500, Sears Surburban's, MTD's, Jeeps & other misc. "treasures"
Location: AL (Southwest)

Re: Super A running problem

Postby staninlowerAL » Sun Feb 14, 2016 8:10 pm

Sounds like you are on the way to success with this one. On another note, there is Pennington 60 inch mower parts list manuals for the different type applications in the pdf manuals above. Stan

Brly
Posts: 19
Joined: Thu May 14, 2015 6:13 pm
Zip Code: 17701

Re: Super A running problem

Postby Brly » Mon Feb 15, 2016 8:28 pm

The Pennington mower is made for a cub. The guy I bought the tractor from had never mounted the mower. It just barely fits. There's about a 1/2" clearance between the rear tractor tires and the deck (my tractor has bigger than stock tires) and when the dolly wheels on the front of the deck are turned just right, theres about 1" clearance with the front tires. I had to cut and re-weld one of the idler pulleys on the bracket to a different location so the belt would run correctly. Lastly, I had to remove the right side deck guard because it hit the right rear tire. But, it does fit and it does work quite well.
Just got in from the garage. I checked all of the manifold to block nuts and they were tight, but that doesn't mean there isn't an air leak there. There's a 1/4" hole in the exhaust part of the manifold, so I'll probably get a new one and a new gasket if I can't find the air leak anywhere else. Planned on doing that eventually anyway. I took the carb off and put some gasket goop on the carb to manifold gasket. This is a suspect area. The boot from the carb to the air cleaner is in bad shape. Another suspect area. I don't have anything to replace it with right now, so I cleaned it up and wrapped it with electrical tape as a temporary fix. I'll see how things go when I can run it again. If the problem is still there, I'll start looking for the leak with starter fluid. Crossing my fingers that what I did tonight will take care of it. We'll see.
Ben

Brly
Posts: 19
Joined: Thu May 14, 2015 6:13 pm
Zip Code: 17701

Re: Super A running problem

Postby Brly » Tue Feb 16, 2016 9:09 pm

Just to wrap this thread up, I went out tonight to spread salt on my driveway that is all ice (love those split brakes) and the tractor runs great! No stumble and all the power is back. I still have some tweaking to do as I think it's running on the rich side now, but at least I found the problem. What a difference a little vacuum leak can make.
Thanks for all the help. Hopefully I can help someone else out.
Ben


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