Cub Carburator Adjustment

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farmergiffIV
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1953 Farmall Cub
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Cub Carburator Adjustment

Postby farmergiffIV » Wed Jul 05, 2017 1:34 pm

Hi there,

So I have been trying to get my cub to start- I need to make sure the carb is set as it should. I just pulled it out of the box its a new original style TM carb.

I have questions that my carburator-to-governor shaft or something with the lever rod assembly is also improperly set up and I need to make sure we are set at 1/3 throttle so I can start up.

What's 1/3 throttle supposed to look like on the throttle butterfly or the throttle lever and shaft assembly of the carb? I'd like to see if I can get the tractor idling without the carburetor-governor shaft assembled.

Right now I turned the idle adjustment screw all the way in and then back out 1 full rotation, any tips on these settings? Thanks

Also, so curious what the original choke throttle on the cub looks like, I think I need to get one as I can't run my electric start w/ out it.
Raptor Creek Farm

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Glen
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Tractors Owned: 1956 Farmall Cub with Fast Hitch, F-11 plow, Disc, Cultivator, Cub-22 mower
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Re: Cub Carburator Adjustment

Postby Glen » Wed Jul 05, 2017 11:36 pm

Hi,
Be careful tightening the gas line connection, or the mounting studs on the IH carburetor, it is soft metal, the threads strip out tightening things too much.
I have found that the idle mixture screw usually needs to be set about 1 1/2 turn open, on the IH carb. The owner's manual tells how to set it. It says warm up the engine before making the setting.

I guess you are saying you don't have the choke lever on the carb, or the choke rod.
The choke rod has a loop on the top end that matches the starter rod loop. The choke rod goes on the left side of the dash.
Here is a new choke rod at TM Tractor, and a new choke lever for the carb.


http://www.tmtractor.com/new/fl/934fp.htm

http://www.tmtractor.com/new/fl/522fp.htm

Here is a pic of from TM Tractor of how the lever for the choke rod goes on the carb, it usually has to be in this position.
Below are pics of the choke rod in position. :)
Attachments
Cub carb.jpg
Cub 3.jpg
Cub.jpg

farmergiffIV
Cub Star
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Posts: 113
Joined: Sat Aug 17, 2013 8:36 pm
Zip Code: 97526
Tractors Owned: 1948 Farmall Cub
1953 Farmall Cub
Location: Oregon

Re: Cub Carburator Adjustment

Postby farmergiffIV » Sun Sep 17, 2017 9:45 pm

Thanks for the helpful information Glen. I'll be getting a replacement choke rod soon. Luckily, I traded a couple of my piglets to a professional mechanic for his trade in some tractor help and he's helped me demystify the carb a little since my original post.
Raptor Creek Farm

outdoors4evr
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Re: Cub Carburator Adjustment

Postby outdoors4evr » Mon Sep 18, 2017 9:10 am

Most adjustable needle valves will be "close" if you turn them in all the way and back them out 1.5 turns.
Finger tight closed is plenty. Don't overtighten it.
184 w/ Creeper & 3-Point
IH 3160a Mower
IH Model 15 Tiller

Matt Kirsch
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Re: Cub Carburator Adjustment

Postby Matt Kirsch » Mon Sep 18, 2017 12:36 pm

If the governor is working properly you "time" the governor to the carburetor by disconnecting the throttle rod on the left side from the governor up front (yoke with a pin through it). Push the throttle lever all the way ahead, which should cause the governor to move ahead where you just disconnected it. Now adjust the length of that throttle rod by turning the yoke in or out on the threads until the pin will just slide through the yoke and governor arm easily, while you hold the throttle on the carburetor wide open.

Generally speaking it does not need much adjustment, so if you find yourself turning it in or out by more than 1 or 2 revolutions, you may be doing it wrong.

Once this adjustment is done the throttle lever should properly control engine speed.

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Glen
5+ Years
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Posts: 1848
Joined: Mon Mar 19, 2012 7:33 pm
Zip Code: 00000
Tractors Owned: 1956 Farmall Cub with Fast Hitch, F-11 plow, Disc, Cultivator, Cub-22 mower
Circle of Safety: Y
Location: Wa.

Re: Cub Carburator Adjustment

Postby Glen » Mon Sep 18, 2017 4:36 pm

Hi,

Matt, here is a page from the Cub service manual, GSS-1411 telling how to adjust the throttle rod, you were talking about. It says open the throttle about half way, not fully. Notice the subject is at 1 on the right side of the page, and then read paragraph A below that.

http://www.farmallcub.info/manuals/gss- ... 002-18.jpg

Then there are 2 more paragraphs on this page, if anyone is wanting the whole procedure. :)

http://www.farmallcub.info/manuals/gss- ... 002-19.jpg


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