Be sure she's breathing throughout.
Fuel cap vent. Through to carb. As well as a happy gravity path. A hot soft fuel line (not saying you have one) can collapse when hot if venting is poor or under much draw. Or kink.(I've a story of a Chevy with a funny gas line.)
Air intake stack.The screen underneath can get loaded up. Oil bath air filter might want peeked at also..
How or when insects had a bad party in my oil bath one year remains a mystery. But my cup runnethed over!
How's the heat on your carb and fuel line? A too hot line might benefit from a heat sink.
Ethanol fuel seemed weak to me.Like not being able to get consistently dialed in under load. Been running rec fuel a long time.
This site uses cookies to maintain login information on FarmallCub.Com. Click the X in the banner upper right corner to close this notice. For more information on our privacy policy, visit this link: Privacy Policy
NEW REGISTERED MEMBERS: Be sure to check your SPAM/JUNK folders for the activation email.
throttle surges
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.
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.
-
- 5+ Years
- Posts: 1140
- Joined: Thu Aug 25, 2016 1:29 pm
- Zip Code: 49343
- Tractors Owned: 48 Farmall Cub "Seen Yore Dobbin"
53 F-Cub W/Loader. - Circle of Safety: Y
- Location: Michigan
-
- Team Cub Mentor
- Posts: 20389
- Joined: Fri Jul 02, 2004 9:52 pm
- Zip Code: 65051
- Circle of Safety: Y
- Location: Mo. Linn
Re: throttle surges
Following is stolen from the internet. Better written than I could say it.52DAVE wrote:I was dragging for about an hour with it Monday when it started to miss. Checked the spark plugs after it cooled down. They were coal black.
Soft, black, sooty dry deposits on plug indicate carbon fouling. Carbon fouling is an indication of a rich air-fuel mixture, weak ignition, or improper heat range (too cold). Carbon deposits are conductive and can create a path for spark plug misfire.
Easy stuff first. Timing light, check ignition timing - and check the advance. Swap coil out with a known good one. Spark plug heat range?Eugene wrote:Double check, then triple check the ignition system.
I'd also compression test the engine and valve tappet adjustment.
I have an excuse. CRS.
-
- Posts: 44
- Joined: Fri Jan 13, 2023 9:58 pm
- Zip Code: 49401
Re: throttle surges
I looked in the service manual and it looked like the idle mixture screw adjusts fuel flow. In that case in would decrease flow. Am I wrong? Does it instead control air flow?
-
- 10+ Years
- Posts: 5003
- 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: throttle surges
Idle mixture screw controls air flow. High speed jet is fixed.
Stan in LA (lower AL)
USAF & Reserves, Reg ARMY, ARMY NG (AL)
USAF & Reserves, Reg ARMY, ARMY NG (AL)
-
- Similar Topics
- Replies
- Views
- Last post
-
- 5
- 142
-
by Don McCombs
Wed May 31, 2023 6:38 am
-
- 2
- 187
-
by Glen
Fri Jul 09, 2021 8:00 pm
-
- 3
- 211
-
by Dominic
Tue May 23, 2023 6:45 pm
-
- 23
- 400
-
by Kalebtrojacek
Wed May 01, 2024 11:24 am
-
- 5
- 178
-
by Glen
Wed Mar 20, 2024 7:35 pm
Who is online
Users browsing this forum: Jim Becker and 7 guests