carb leaking

The Cub Club -- Questions and answers to all of your Cub related issues.

Moderator: Team Cub

Forum rules
Notice: For sale and wanted posts are not allowed in this forum. Please use our free classifieds or one of our site sponsors for your tractor and parts needs.
kully560
5+ Years
5+ Years
Posts: 72
Joined: Tue Apr 05, 2016 3:11 pm
Zip Code: 11727

carb leaking

Postby kully560 » Tue Jul 13, 2021 2:19 pm

hello again,I need some help , my 1959 i/h cub low boy has a gas leak at the carb choke shaft on both sides, is this rebuildable or do In need a new carb? if there is a kit where is the best place to purchase it? as for the carb I do not want a china nock off from ebay any suggestions thanks

Bob McCarty
Team Cub
Team Cub
Posts: 10806
Joined: Tue May 25, 2004 8:02 pm
Zip Code: 80501
Tractors Owned: Cubs, MH Pony, Shaw, Allis G, 1934 Silver King, JD LA and LI, Gibson D, David Bradley Tri-Trac
Circle of Safety: Y
Location: CO, Longmont

Re: carb leaking

Postby Bob McCarty » Tue Jul 13, 2021 2:48 pm

Is this an IH or Zenith carb?
"We don't need to think more,
we need to think differently."
-Albert Einstein

User avatar
Don McCombs
Team Cub Mentor
Team Cub Mentor
Posts: 15580
Joined: Mon Feb 03, 2003 6:45 am
Zip Code: 21550
Tractors Owned: "1950 Something" Farmall Cub
1957 Farmall Cub w/FH
1977 International Cub w/FH
1978 International Cub
1948 Farmall Super A
Circle of Safety: Y
Location: MD, Deep Creek Lake

Re: carb leaking

Postby Don McCombs » Tue Jul 13, 2021 2:52 pm

Under normal circumstances, there should be no raw fuel in the area of the choke shaft and plate. You need to look deeper for the source of your leakage. I would recommend starting with a check of the float adjustment.
Image
Don McCombs
MD, Deep Creek Lake

Image
Proud Member of Maryland Chapter 39
Circle of Safety

kully560
5+ Years
5+ Years
Posts: 72
Joined: Tue Apr 05, 2016 3:11 pm
Zip Code: 11727

Re: carb leaking

Postby kully560 » Tue Jul 13, 2021 6:16 pm

to answer Bobs question I do not know who makes the carb but I do know the tractors history and it is all original if that helps. also thanks Don I will look deeper .

NJ Farmer
10+ Years
10+ Years
Posts: 191
Joined: Fri Feb 04, 2005 7:20 pm
Zip Code: 08876
Tractors Owned: 1953 F-Cub
1956 Lo-Boy
1971 Cub Cadet 149

Re: carb leaking

Postby NJ Farmer » Tue Jul 13, 2021 7:05 pm

If your carb is leaking at the choke shaft your float is either sunk or float setting is too high. The carb can be rebuilt but it needs to be rebuilt following the service manual to get the correct float setting. When you get it apart shake the float….if it has fluid in it it’s garbage.
If not reset the float height following the service manual.

NJ Farmer

Eugene
Team Cub Mentor
Team Cub Mentor
Posts: 19235
Joined: Fri Jul 02, 2004 9:52 pm
Zip Code: 65051
Circle of Safety: Y
Location: Mo. Linn

Re: carb leaking

Postby Eugene » Tue Jul 13, 2021 7:37 pm

Leaking out the choke shaft, both sides. That's a lot of fuel in the air cleaner hose.

Drop the air cleaner bowl. Clean and let any fuel evaporate from the air cleaner.

As stated, the problem is with the needle valve, seat gasket, or float.

Suggest doing a bench test for the leak source.

Edit: After you get the carb fix and before starting engine; check the engine oil for fuel smell, remove spark plugs and crank engine over without starting.
I have an excuse. CRS.

User avatar
Dale Finch
10+ Years
10+ Years
Posts: 5524
Joined: Tue Apr 27, 2010 11:34 am
Zip Code: 27517
Tractors Owned: '51 Cub "Bernie" with Fast Hitch
'55 Cub "Bruno" with Woods 59 mower
'55 Cub "Bertha" with Woods 42 mower
'55 Cub "Ben" with Woods 42 mower
'56 Cub "Boris" with Mott Flail mower
Circle of Safety: Y
Location: NC, Chapel Hill

Re: carb leaking

Postby Dale Finch » Tue Jul 13, 2021 8:05 pm

Are you sure the fuel is not dripping out the bottom, where there is a drain? It will do that after an unsuccessful start attempt...normal.
Dale Finch
Image
Circle of Safety

User avatar
Glen
5+ Years
5+ Years
Posts: 5020
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: carb leaking

Postby Glen » Tue Jul 13, 2021 8:25 pm

Hi,
The IH carburetor is what came on a 1959 LoBoy, and many other years of Cubs.
IH started using the Zenith carb during 1975, and people have put them on other years of Cubs and LoBoys.

Below are pics from TM Tractor.

The 1st pic is an IH carb, they usually have 2 IHs cast into them.

The 2nd pic is the bottom of the IH carb, showing the drain hole for excess gas, if any gets into the air intake. The hole has a filter material in it. If it is plugged with dirt, gas couldn't drip out of it.
Gas is supposed to drip out the hole, if needed.
If the carb is working right, no gas would drip out of it when sitting.
If you try to start the Cub and it doesn't run, gas can drip out the hole then, like Dale said above.

The 3rd pic is a Zenith carb.
The Zenith carb uses a different float level than an IH carb.

You have to take the carb apart to set the float level.
When removing the top from the IH carb, pull the 2 halves straight apart for 3 or 4 inches.
There is a small idle tube that is attached to the top half, and sticks down into the bottom half.
If you twist the 2 halves apart, you can break the idle tube.

TM Tractor has individual carb parts. :)
Attachments
Cub carb 9.jpg
Cub carb 6.jpg
Cub carb Z 2.jpg

kully560
5+ Years
5+ Years
Posts: 72
Joined: Tue Apr 05, 2016 3:11 pm
Zip Code: 11727

Re: carb leaking

Postby kully560 » Thu Jul 22, 2021 7:03 am

thanks for all the help , it was a clog screen like Glen suggested , all good now!!

User avatar
Stanton
Team Cub
Team Cub
Posts: 7061
Joined: Mon Jun 22, 2009 6:56 am
Zip Code: 64070
Tractors Owned: 1942 Farmall AV, serial #87025
1947 Farmall Circle Cub, serial #2116
1948 Farmall Cub, serial #46066
Circle of Safety: Y
Location: Lone Jack, MO

Re: carb leaking

Postby Stanton » Thu Jul 22, 2021 2:06 pm

kully560 wrote:thanks for all the help , it was a clog screen like Glen suggested , all good now!!


Was the bottom drain filler material clogged, preventing gas from draining out the bottom? I'm having a hard time believing your carb woes are over if you have enough gas inside the air intake compartment to cause gas to drip, then the float still needs to be addressed.

carb.JPG
Air intake compartment.
carb.JPG (29.13 KiB) Viewed 269 times


If you ever need a rebuilt kit, then I'd recommend McDonald Carb, found here: https://www.mcdonaldcarb.com/category_s/359.htm
Stanton
Image Circle of Safety

kully560
5+ Years
5+ Years
Posts: 72
Joined: Tue Apr 05, 2016 3:11 pm
Zip Code: 11727

Re: carb leaking

Postby kully560 » Fri Jul 23, 2021 4:35 pm

the screen was clog , I removed the air filter rubber hose and sprayed carb cleaner into the screen and when the motor runs now I hear a little whistle like air passing through the screen . I do not think it is the float as the carb is original and the tractor has never been mess with .could be maybe I did not have the fuel shut off valve closed tight enough and gas drip out of the choke shaft instead of the screen . but all looks good so far , thanks

User avatar
Rick Spivey
Cub Pro
Cub Pro
Posts: 2580
Joined: Sun Jul 01, 2007 10:07 pm
Zip Code: 29518
Circle of Safety: Y
Location: SC, Cades 29518

Re: carb leaking

Postby Rick Spivey » Sat Jul 24, 2021 6:48 am

If you are talking about the screen wire in the air cleaner, then I recommend you remove the air cleaner from the engine and soak it in kerosene, varsol, etc. It should let more air in than just a "whistle", I suspect it is still quite clogged. Some folks may think the screen you were talking about is the small screen located where the fuel line enters the carburetor; if that is correct, please clarify so we can continue to guide your efforts to resolve the issue.
Rick Spivey
'52 Cub ("Great Personality") 148xxx
'48 Cub with FH ("Gunny Cub") 38xxx
'57 Lambretta (a slow work in progress)
'74 Triumph TR6 (Mama's toy)

kully560
5+ Years
5+ Years
Posts: 72
Joined: Tue Apr 05, 2016 3:11 pm
Zip Code: 11727

Re: carb leaking

Postby kully560 » Sat Jul 24, 2021 6:54 am

it is the small screen on the carb. just past where the air filter hose enters the carb on the bottom under where the choke shaft is .

Gary Dotson
Team Cub Mentor
Team Cub Mentor
Posts: 4511
Joined: Thu Aug 03, 2006 6:20 am
Zip Code: 43358
Tractors Owned: 48 Cub Diesel (Cubota)
53 Cockshutt 20 restored (Shooter)
52 Cockshutt 20 unrestored
47 Leader "B" (Herckie)
49 Leader "D" (Princess)
49 Leader "D" very rough
48 Leader "D" unrestored
Kubota B6200E
Kubota B6200HST
Kubota B8200HST-D
Circle of Safety: Y
Location: OH West Mansfield

Re: carb leaking

Postby Gary Dotson » Sat Jul 24, 2021 7:11 am

He’s referring to the drip screen just behind the choke plate, Rick.

User avatar
Rick Spivey
Cub Pro
Cub Pro
Posts: 2580
Joined: Sun Jul 01, 2007 10:07 pm
Zip Code: 29518
Circle of Safety: Y
Location: SC, Cades 29518

Re: carb leaking

Postby Rick Spivey » Sun Jul 25, 2021 9:02 am

Well, that's the screen I didn't think of! That clearly points to a needle/seat allowing too much gas into the carburetor; however, I once had a similar issue where the discharge nozzle was loose, and allowed fuel to keep flowing into the carburetor throat. Your carburetor needs a good review to insure proper function.
Rick Spivey
'52 Cub ("Great Personality") 148xxx
'48 Cub with FH ("Gunny Cub") 38xxx
'57 Lambretta (a slow work in progress)
'74 Triumph TR6 (Mama's toy)


  • Similar Topics
    Replies
    Views
    Last post

Return to “Farmall Cub”

Who is online

Users browsing this forum: bookman51, Ken (48 Cub) and 7 guests