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

Tractor Talk Discussion Forum

Magneto ignition

Welcome Guest, Log in or Register
Author 
Walter

05-13-2004 13:02:36




Report to Moderator

I'm trying to get my Swiss-made 1960 Rapid 2 cylinder walk-behind tractor started. I think there is a magneto problem, as I have no spark.
I happen to have a new replacement ignition magneto coil that mounts on the flywheel, but I don't want to use it unless the old one is bad. Both the old and new coils have two wires, a large high-voltage secondary that goes to the distributor cap and a low voltage that goes to the points. The high voltage shows 5K ohms to ground, whereas the low voltage shows zero ohms to ground. Is this normal, or does it mean they are both shorted out. That would be odd since the new one is new and unused. Maybe both coils are fine and the problem is somewhere else. Is there any way to troubleshoot the system? Any magneto experts out there?

[Log in to Reply]   [No Email]
RobertTX

05-14-2004 07:07:48




Report to Moderator
 Re: Magneto ignition in reply to Walter, 05-13-2004 13:02:36  
Your symptoms and the short to ground suggest a bad condenser. Isolate the condenser and check it with your meter, it should read as an open if you measure across the wire going to it and ground.

A good way for a quick troubleshoot is to crank it in the dark and watch the points closely for blue spark. If you see no spark or a weak orange spark, the primary system has problems. If the points show good spark, move on the secondary. Good luck.

[Log in to Reply]  [No Email]
Walter

05-14-2004 10:59:06




Report to Moderator
 Re: Re: Magneto ignition in reply to RobertTX, 05-14-2004 07:07:48  
Thanks, Robert. I had swapped the condenser with another, but it's worth testing it definitively. I'll check for the spark at the points.



[Log in to Reply]  [No Email]
RAB

05-13-2004 15:17:24




Report to Moderator
 Re: Magneto ignition in reply to Walter, 05-13-2004 13:02:36  
Walter,
You need to stick to design specs for the ignition system. Timing and points opening are critical in that the flywheel must be generating current at the time the points open or there will be no magnetic flux energy to interupt to create the high tension voltage.
Point cleanliness is very important, and you might check that the condenser is not faulty (check with a multimeter set on ohms - should show an initial low reading rising steadily, possibly to several mega-ohms).
These systems are simple, but can be a headache to get them working - like points shorting to earth when open, or screw connections shorting inside the flywheel, but only at that important fraction of a turn when you want that spark!
Hang in there, it WILL work!!
Regards, RAB

[Log in to Reply]  [No Email]
Walter

05-14-2004 02:31:15




Report to Moderator
 Re: Re: Magneto ignition in reply to RAB, 05-13-2004 15:17:24  
Thanks, That's good advice. Is there any way to isolate and test the other components so I can troubleshoot step-by-step? I'm doing visual checks, but the fact that the coil primary is virtually zero ohms to ground, means that checking for a short on that whole side of the circuit seems impossible.



[Log in to Reply]  [No Email]
RAB

05-14-2004 15:38:23




Report to Moderator
 Re: Re: Re: Magneto ignition in reply to Walter, 05-14-2004 02:31:15  
Can you remove that ground connection. You will then know it doesn't have an unwanted short circuit.
Regards, RAB



[Log in to Reply]  [No Email]
Walter

05-17-2004 09:18:26




Report to Moderator
 Re: Re: Re: Re: Magneto ignition in reply to RAB, 05-14-2004 15:38:23  
I've got a fat, blue spark this morning. There were several things that needed attention, with the problem compounded by spare parts that were not all functional. Your advice gave me a clear troubleshooting path to follow. Many thanks.



[Log in to Reply]  [No Email]
Walter

05-15-2004 06:03:22




Report to Moderator
 Re: Re: Re: Re: Magneto ignition in reply to RAB, 05-14-2004 15:38:23  
That's a good idea. It didn't occur to me. Thanks.



[Log in to Reply]  [No Email]
Mark

05-13-2004 14:59:25




Report to Moderator
 Re: Magneto ignition in reply to Walter, 05-13-2004 13:02:36  
on most magneto's, the points are set at,015-.020. .030 seems to wide.



[Log in to Reply]  [No Email]
rustyfarmall

05-13-2004 13:26:52




Report to Moderator
 Re: Magneto ignition in reply to Walter, 05-13-2004 13:02:36  
What do the contact points look like? That is usually the first thing to consider when you don't have any fire.



[Log in to Reply]  [No Email]
Walter

05-13-2004 13:58:21




Report to Moderator
 Re: Re: Magneto ignition in reply to rustyfarmall, 05-13-2004 13:26:52  
The points look OK. The machine was running OK but quitting when hot. Then it quit and wouldn't restart. I found several problems, shorted wires, bad ignition wires, etc, and corrected them all. I checked the timing and set the points to open about 30 degrees before TDC, so as to synchronize the magneto. Still no spark. (By the way, I now realize that a near zero primary-to-ground reading is normal for a coil)

[Log in to Reply]  [No Email]
rustyfarmall

05-13-2004 14:28:03




Report to Moderator
 Re: Re: Re: Magneto ignition in reply to Walter, 05-13-2004 13:58:21  
I am guessing that you have overlooked something, not to imply that you were not thorough, but oftentimes those gremlins can be real hard to find. Keep looking, most likely when you find the problem you will wonder how you could have missed it.



[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