Carb Leaking Gas

The Cub Club -- Questions and answers to all of your Cub related issues.
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.
Posts: 7
Joined: Wed Jun 01, 2022 11:50 am
Zip Code: 17543

Carb Leaking Gas

Postby lititzdoug » Tue Jul 19, 2022 1:54 pm

I have a 1948 Cub that starts and runs nice. When I shut it off and close the fuel valve, I will have gas dripping out of the carburetor. The time varies from a few minutes to overnight. Gas tank is clean, sediment bowl is clean. Any thoughts? Thank you!

501 Club
501 Club
Posts: 1853
Joined: Wed Jan 20, 2021 8:21 pm
Zip Code: 44410
Tractors Owned: 1968 Cub Fast Hitch
LF-1 Platform Carrier
144 Cultivators
L-F194 Plow(s)
F38 Disk
L-F3 Spring Tooth Harrow
CS Bell No. 60 Grain Mill on a unmodified Fast Hitch Disk hitch prong
Home Made Fast Hitch Potato Plow
54A Blade

Couple 1948 Cubs
172 Runner Planter
53 Fertilizer
Cub-3 Field Cultivator
Cub-189 Two Way Plow
Cub-22 Sickle Bar Mower
Mechanical Transplanter with side mount barrel (needs a fast hitch adapter) :)

Misc Belly Mowers

Wish List
International 100 Fast Hitch Blade
Mott Fast Hitch Flail Mower

Wish Wish Wish List
Fast Hitch Rotary Hoe
4E hammer mill
Location: Ne Ohio

Re: Carb Leaking Gas

Postby SamsFarm » Tue Jul 19, 2022 2:10 pm

Could be;

Stuck float
Bad needle and / or seat

Bob McCarty
Team Cub
Team Cub
Posts: 11954
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 Gas

Postby Bob McCarty » Tue Jul 19, 2022 2:50 pm

If it's leaking after the sediment bowl valve is closed, there is probably debris keeping the valve seat from completely closing.
"We don't need to think more,
we need to think differently."
-Albert Einstein

Cub Star
Cub Star
Posts: 85
Joined: Tue Jul 19, 2022 12:48 pm
Zip Code: 00000
Tractors Owned: 1948 Farmall Cub with 22 sickle mower,Grader blade with brackets for snow plow, Swaying draw bar,193 moldboard plow and a spring tooth field cultivator.

Re: Carb Leaking Gas

Postby RedFred » Tue Jul 19, 2022 3:37 pm

Where is it leaking?

Team Cub Mentor
Team Cub Mentor
Posts: 20505
Joined: Fri Jul 02, 2004 9:52 pm
Zip Code: 65051
Circle of Safety: Y
Location: Mo. Linn

Re: Carb Leaking Gas

Postby Eugene » Tue Jul 19, 2022 3:53 pm

RedFred wrote:Where is it leaking?
Dripping out the carburetor after fuel shut off at tank. Indicates two problem areas. Shut off valve and needle valve/seat.
I have an excuse. CRS.

10+ Years
10+ Years
Posts: 5074
Joined: Fri Oct 29, 2010 11:34 pm
Zip Code: 36558
Tractors Owned: Cubs: (3)'49's, (1 is for parts), (1)'57 IH Cub LoBoy w/FH, (2)154 Number Series Loboys, (1 is for parts), '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, '47 & '49 Avery V, '53 MM BG (offset), '51 JD M (regular), '56 JD 420C, with Blade and fire plow, '85 JD 850 (Yanmar) w/72" belly mower, '76? Yanmar 2TR15 1500 & Bush Hog SQ42S-2 mower, '78? FORD Dexta, '86 FORD LGT14D & 48" Mower, (2)Cub Cadets & Mowers (MTD), (4) Sears Surburban's, other MTD mowers, Jeeps & other misc. "treasures"
Circle of Safety: Y
Location: AL (Southwest)

Re: Carb Leaking Gas

Postby staninlowerAL » Tue Jul 19, 2022 4:15 pm

Does it leak when the shutoff valve on the bottom of the tank is closed? I had a problamatic fuel shutoff valve and decided to install a quick open ball valve downstream from the sediment bowl. Here's how I made it work:
Stan in LA (lower AL)
USAF & Reserves, Reg ARMY, ARMY NG (AL)

Posts: 7
Joined: Wed Jun 01, 2022 11:50 am
Zip Code: 17543

Re: Carb Leaking Gas

Postby lititzdoug » Wed Jul 20, 2022 5:41 am

I opened the drain screw last evening to bleed the supply line and the carburetor. It stopped for a time then started leaking again. I am guessing that this tells me that flow is bypassing the closed valve because of debris or improper seating of the needle.

User avatar
Cub Pro
Cub Pro
Posts: 7760
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 Gas

Postby Stanton » Wed Jul 20, 2022 6:55 am

Lots of helpful threads about fuel in the How To forum. The ones by Lurker Carl are particularly good. Located here:

Sounds like nothing short of a careful disassembly and cleaning are in your near future. Ask us questions as/if you need to…
Image Circle of Safety

10+ Years
10+ Years
Posts: 825
Joined: Sun Apr 10, 2005 9:25 pm
Zip Code: 40165
Location: bullitt county, kentucky

Re: Carb Leaking Gas

Postby CharlieK » Wed Jul 20, 2022 9:38 am

thanks Stanton
get er done; life is good

Posts: 7
Joined: Wed Jun 01, 2022 11:50 am
Zip Code: 17543

Re: Carb Leaking Gas

Postby lititzdoug » Thu Jul 21, 2022 8:14 am

Thanks to everyone for the feedback. As always, I am impressed with the knowledge of this group and willingness to share that knowledge.

  • Similar Topics
    Last post

Return to “Farmall Cub”

Who is online

Users browsing this forum: No registered users and 3 guests