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

Shop Now

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

Attention Forum Users: On the 28th of December 2023 at 9:00am Central Time, we will be taking the forums down for maintenance while we prepare the new forums for your use. Please click here for more information.

Minneapolis Moline Tractors Discussion Forum
:

magneto drive

Welcome Guest, Log in or Register
Author 
dlp

09-22-2004 18:09:45




Report to Moderator

I"m wanting to put a mag on a 206 engine. I figure the tower shaft that drives it might be different. Is it different & are there any other changes that I need to make? Thanks!




[Log in to Reply]   [No Email]
dlp

09-24-2004 17:59:19




Report to Moderator
 Re: magneto drive in reply to dlp, 09-22-2004 18:09:45  
I found out that the gear on the tower shaft & the gear on the cam are different than in a distributor engine. I want a mag so I can ditch some weight by deleting the battery, starter, & battery box. I want to get it down under 3500#, so I'm deleting as much as possible. I am going to need both gears, mine are rusted to badly to use.



[Log in to Reply]  [No Email]
MMark

09-25-2004 05:47:04




Report to Moderator
 Re: magneto drive in reply to dlp, 09-24-2004 17:59:19  
Sorry About the post I wrote I went braindead for a minute. R and Z mags spin crankshaft speed, distributors spin camshaft speed. So you will have to change the gears. 24 tooth on the cam, 12 on the oil pump shaft. I work on so many JD mags I opened my mouth before my brain. JD 2 cyl mags spin camshaft speed. So you can interchange distributor to mag or vise-versa.

Sorry about the confusion,
Mark Damewood

[Log in to Reply]  [No Email]
Kelvin

09-23-2004 17:58:31




Report to Moderator
 Re: magneto drive in reply to dlp, 09-22-2004 18:09:45  
You have to change both the oil pump drive gear on the camshaft and the oil pump shaft. If you have distribuitor ignition, they both have 16 teeth. For magneto ignition, the drive gear on the camshaft will have 24 teeth and the driven gear on the oil pump shaft will have 12 teeth. (So the oil pump shaft will turn twice as fast as the cam. This helps the magneto produce a good spark at low rpm.)

The oil pressure relief might have to be adjusted-the pump would now spin twice as fast as it used to.

As far as the shafts themselves, there is no difference, aside from the above mentioned gear ratios.

O.K. I'm curious-Why are you wanting to do this?

[Log in to Reply]  [No Email]
Kelvin

09-23-2004 18:01:40




Report to Moderator
 Re: magneto drive in reply to Kelvin, 09-23-2004 17:58:31  
Whoops! forgot to mention that in most situations, you will also have to change to a distribuitor drive coupling at the top of the oil pump shaft.

Why do I say most situations? -There may be a few distribuitors out there that were supplied with a coupling that fit the magneto coupling on the oil pump shaft.



[Log in to Reply]  [No Email]
Mopower

09-23-2004 04:53:15




Report to Moderator
 Re: magneto drive in reply to dlp, 09-22-2004 18:09:45  
You might take a look at the cam gear that drives the shaft. I think it is different as well.



[Log in to Reply]  [No Email]
MMark

09-24-2004 06:17:07




Report to Moderator
 Re: magneto drive in reply to Mopower, 09-23-2004 04:53:15  
I may be wrong here, but doesn't a mag and a distributor spin the same rpm (1/2 the rpm as the crank) The impulse on the mag does two things it retards the spark so you don't get kicked when you hand crank and it springs the mag through faster to aid in low rpm firing of the mag. There should be no difference in the cam or oil pump/mag/dist gears. The distributor mounts to what looks like the backside of a mag. I think all you need to do is to remove that distributor mount and (I believe) the oil pump shaft has to be rotated 90 degrees, if you don't the mag wont line up to the correct mounting lugs. (there is one less coupling when using a mag, hence the 90 degree difference) There may be a different drive lug for mag verses distributor but I don't think so.

Mark Damewood

[Log in to Reply]  [No Email]
Heath

09-26-2004 15:08:44




Report to Moderator
 Re: magneto drive in reply to MMark, 09-24-2004 06:17:07  
I just completed converting my 1940 R from magneto drive to distributor drive so I cound then install electronic ignition inside my Delco distributor. I have all the parts for the mag drive if you need them. Will sell them to you reasonably - just e-mail me at [email protected]. I'll tell you what, I've never seen a 6 volt tractor start so quick(it's freshly overhauled too). I'm a believer! Here's how I changed mine out....with the mag/dist. off the tractor, start by dropping the oil pump which is bolted to the bottom of the crankcase. When you get it off, firmly pull the gear off of the bottom of shaft. The gear is held on the shaft by two small woodruff keys. It took a little work to get mine out. When these are out, look at the front of the crankcase under the fan mounting, and you will find a set screw. Remove it by backing the nut off and use a large slotted screw driver to back set screw out(I had to remove my radiator to get good enough leverage and room to work). Next I removed the large engine side cover and valve covers. Remove rocker arms. Remove camshaft by taking the four bearing caps off(take note of the way they came off, because the top of the bearing caps have grooves to allow oil to run in from the top). I then put the cam on the bench and heated the gear to drive it off. Then I put camshaft in the deep freeze for a couple of hours(the next day) to shrink it before I drove the new gear on. After shrinking, the gear drove on firm, but not hard. I didn't heat the new gear. Don't forget to re-install the washers and bolt on end of cam. When you re-install cam, there should be about .003 clearance between the gears and the front bearing cap. I had to heat and adjust mine after I got the gear on and test fit it. Be sure to allign your timing marks when you put everything back together. Also, the slot in the drive coupling should be parallel with the crankshaft for magnetos, and cross-wise with the crankshaft for distributors when on TDC #1. When you re-install the oil pump, you are supposed to use 4 paper gaskets together for the right fit, which I did. I used high-tach sealant between each layer to prevent oil leaks. I put everything back together like I took it apart. Don't forget to re-tighten the set screw in front again. The only thing I'm disappointed in now is I seem to have valve float at higher RPMs. I should get all new springs and change them out. They are pretty easy to change on these tractors. Does anyone have any suggestions on a good replacement spring for an R or Z? My machinist used 350 Chevy valves in the head. Maybe those 350 springs would work too?

[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