Welcome! Please use the navigational links to explore our website.
Company Logo (800) 853-2651 Shop Now
   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver

Allis Chalmers Discussion Forum

C Allis Magneto-Spark on only 2 cylinders

Welcome Guest, Log in or Register
Author  [Modern View]

07-27-2008 14:19:00

Report to Moderator

I have a '47 C with a Fairbanks-Morse magneto that only has spark on two cylinders. I thought this would be a cap or rotor problem so I replaced both the cap and the rotor (not with a new one, but from another running tractor). I still have the same problem. No spark on the same two cylinders. I have checked the plugs and wires on the two problematic cylinders to see if they work, and they do. Does anyone have any recommendations as to what I should check next? Thank you.

[Log in to Reply]   [No Email]
Steve in NJ

07-30-2008 03:36:21

Report to Moderator
 Re: C Allis Magneto-Spark on only 2 cylinders in reply to JordanNC, 07-27-2008 14:19:00  
The problem could be a very weak magnetic field at the magnetic rotor. If that is the problem, re-magnetizing the rotor assembly is the fix. I've had mags come in for repair that had the problem, when I first ran them on the bench, and after a good rebuild and re-magnetizing the rotor assembly, the fire is back at all four holes with a vengence. Another problem F/M had with its early version Mags is the tar-taped coil that was used. These coils would "leak" to where stray spikes would ground to the inside of the Mag housing and either kill the engine or kill a cylinder or two. HTH

[Log in to Reply]  [No Email]

07-28-2008 20:48:28

Report to Moderator
 Re: C Allis Magneto-Spark on only 2 cylinders in reply to JordanNC, 07-27-2008 14:19:00  
Are you sure that it's not a John Deere mag?! LOL

[Log in to Reply]  [No Email]
Kentb of SWMO

07-27-2008 15:06:45

Report to Moderator
 Re: C Allis Magneto-Spark on only 2 cylinders in reply to JordanNC, 07-27-2008 14:19:00  
Has someone installed one of the solid-state chip that replace the points and condenser? If so this will cause it to fire on anly two cylinders. It will fire, skip, fire and skip.


[Log in to Reply]  [No Email]
El Toro

07-27-2008 14:31:16

Report to Moderator
 Re: C Allis Magneto-Spark on only 2 cylinders in reply to JordanNC, 07-27-2008 14:19:00  
Have you checked the lobes on the mag for being worn flat? See if there's any slop in that mag's shaft with the lobes. Hal

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

Hop to:

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

Today's Featured Article - Product Review: Storm Covers - by Staff. We recently had a chance to try out the new Storm Cover for the Ford 9N, 2N and 8N tractor that is now being re-introduced to a new generation of Ford N-Series tractor owners. Originally produced more than 40 years ago, it is now enjoying a reproduction run that has been licensed by the Ford Motor Company. An original storm cover was used for the pattern, and this reproduction cover is indeed exactly as the original (of which we had previously only seen pictures of in miscellaneous old sale ... [Read Article]

Latest Ad: International and John deere suitcase weights. [More Ads]

Copyright © 1997-2022 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