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
:

Magneto timing question

Welcome Guest, Log in or Register
Author 
spray004

07-05-2006 05:29:41




Report to Moderator

I have a '48 B with an H4 magneto. I am trying to set the timing correctly on magneto itself. My question is when the magneto snaps and the rotor spins, where should it stop at? Should it stop under each post on the cap? When I installed mine it will snap and spin past each post and stop in between. I have the small gears on the front of the magneto set correctly (small gear with notch out of one tooth is directly lined up with the R on the larger gear).

Thanks

[Log in to Reply]   [No Email]
MAGMAN

07-05-2006 15:16:24




Report to Moderator
 Re: Magneto timing question in reply to spray004, 07-05-2006 05:29:41  
HI Spray, That sounds right when the trip trips it goes from just at or before the wire on the cap across the wire and ends up about half way between the next cyl on the cap. After you run her for a few hours or more you can look at the studs in the cap and see where the black is on them and mmove the rotor gear if you need to to get it centered. JON



[Log in to Reply]  [No Email]
spray004

07-05-2006 10:19:51




Report to Moderator
 Re: Magneto timing question in reply to spray004, 07-05-2006 05:29:41  
Ok from what I'm reading then I have it set correctly. With the #1 piston at TDC, the rotor is roughly at the 12 o'clock position, after I turn the crank, the magneto will snap and the rotor will stop at around the 4 o'clock position or so.



[Log in to Reply]  [No Email]
Bob

07-05-2006 06:05:32




Report to Moderator
 Re: Magneto timing question in reply to spray004, 07-05-2006 05:29:41  
Before a the mag "trips", the rotor will be AHEAD OF the cap terminal it's going to fire, after the impulse "snaps", the rotor will be AFTER the terminal it just fired. Completely normal.

That's what makes it hard for folks who try to set the position of the rotor without looking at the timing marks on the gears... the correct postion of the rotor seems illogical.



[Log in to Reply]  [No Email]
Bob/Ont

07-05-2006 05:53:51




Report to Moderator
 Re: Magneto timing question in reply to spray004, 07-05-2006 05:29:41  
My W4 manual says to set the engine on TDC mark and with the mag bolts loose rotate the mag untill it clicks then tighten up the bolts. The impulse coupling holds the mag rotation untill you are over TDC then it lets go so it will always end up past the mark as you say when it stops. Be very carefull the first time you crank it after adjusting. If you get it advanced and it lets go before TDC it will spin the crank back at you and that Hurts.
Later Bob

[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