Welcome! Please use the navigational links to explore our website.
PartsASAP LogoCompany Logo Auction Link (800) 853-2651

Shop Now

   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver

Farmall & IHC Tractors Discussion Forum
Order Farmall Cub Parts Online

Farmall Cub - Carb tuning? after recent upgrades

Welcome Guest, Log in or Register
Author 
dave in york ha

10-11-2006 04:38:22




Report to Moderator

I have a 1949 Farmall Cub which I recently replaced dist cap and wiring between dist cap and plugs, and replaced condensor and points and figured out how to re-gap the points. She's purring now. The only problem I'm having right now is what seems to be a fuel flow problem or a too-lean condition-I'm not sure, which is why I'm posting here, for expert opinions. I have a 5' mower deck which I use to cut field grass for years(always in 1st gear). The problem I'm having with the Cub now is when going up a hill, or on a level and engaging the PTO for the mower, the engine will sputter and die. It will restart just fine. My father-in-law says the carb is probably running too lean. I see the adjustment screw on the top backside of the carb which I'm assuming adjusts the air/unleaded gas mixture ratio. How EXACTLY do I adjust this to know when it is running at a more optimum setting? When running in neutral on a flat, I can turn it a couple of full rotations in one direction or the other, with no discernable difference in engine sound. Is the fine tuning also performed while running it in neutral and playing with the choke?
I also have noted on serveral occasions that sometimes the carb picks up a fine coating of gasoline, especially after I open the gas line prior to starting the tractor, and it leaks then. It 'dries up' after the tractor is running. I also noted that when the tractor is running, sometimes when it is sputtering around, if I gently tap the bottom or side of the carb where the float is, the engine seems to pick up power, as if it is getting more gas. What is my next logical step-replace the float? I'd appreciate detailed instructions here or a link to them on troubleshooting/fine tuning a carb, if that's what you think is the problem. I do NOT have the owner's manual, but I have a service manual on the Cub, but the procedure is not there-go figure.
Sincerely and with much thanks,
Dave Rhan

[Log in to Reply]   [No Email]
John M

10-11-2006 15:55:24




Report to Moderator
 Re: Farmall Cub - Carb tuning? after recent upgrad in reply to dave in york haven pa, 10-11-2006 04:38:22  
Sounds to me like you have a float problem, all of the symptoms, except the fuel weeping, sound like an incorrectly set float, or a hanging float. Either way I would suggest since you will have to take it off and replace that gasket and check your float, just go ahead and rebuild it.



[Log in to Reply]  [No Email]
glennster

10-11-2006 06:02:35




Report to Moderator
 Re: Farmall Cub - Carb tuning? after recent upgrad in reply to dave in york haven pa, 10-11-2006 04:38:22  
could be a couple of things. first check your fuel flow from the tank, disconnect the line at the carb and see if you get good flow. may be stuff in the tank. second sounds like the float is hanging up a little. i would pull the bowl and look for dirt in there. the fuel weep on the outside sounds like a gasket leaking. could also be a vaccuum leak at the throttle cross shaft or bowl gasket. easy way to check is to start the engine let it warm up a little, gently spray ether starting fluid at the carb, be sure intake pipe is on, if it has a vaccuum leak it will pull ether in and you will here the engine change sound. it will either be the gasket to intake manifold or the bowl gasket that leaks.

[Log in to Reply]  [No Email]
Larry in WNY

10-11-2006 09:36:49




Report to Moderator
 Re: Farmall Cub - Carb tuning? after recent upgrad in reply to glennster, 10-11-2006 06:02:35  
Dave,

When you disconnect the fuel line from the carb., there is a filter in the carb. inlet that may be full of dirt/rust from the tank causing reduced fuel flow.

Larry



[Log in to Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:


TRACTOR PARTS TRACTOR MANUALS
We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

Home  |  Forums


Copyright © 1997-2023 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters

Website Accessibility Policy