Fairbanks magneto

[Anthonypeet]

I've got a question about my Allis Chalmers b I have a 39 with front plow and a 4 8 with woods belly mower both of The magnetos went bad on me. I know it's the coil because if I run the tractor for a while it gets hot and shuts down and fit cools down or if I run cold water on the magneto it'll fire back up so I know that's the problem. But my other problem on both of them is the spring broke so I'm getting zero spark and the spring would be the coiled spring where you would snap. So I bought another magneto from a farmer. Worked great and same thing happened. Coil went bad. It gets hot. It shuts down. I've gone to other places that work on tractors and when I talk to their mechanics it's like I'm speaking Chinese to them. They have zero clue so I was going to attempt to find by the coiled spring and coil and do it myself. Has anybody done such a thing? It's just frustrating. Nobody knows anything

 

[wore out]

I've got a question about my Allis Chalmers b I have a 39 with front plow and a 4 8 with woods belly mower both of The magnetos went bad on me. I know it's the coil because if I run the tractor for a while it gets hot and shuts down and fit cools down or if I run cold water on the magneto it'll fire back up so I know that's the problem. But my other problem on both of them is the spring broke so I'm getting zero spark and the spring would be the coiled spring where you would snap. So I bought another magneto from a farmer. Worked great and same thing happened. Coil went bad. It gets hot. It shuts down. I've gone to other places that work on tractors and when I talk to their mechanics it's like I'm speaking Chinese to them. They have zero clue so I was going to attempt to find by the coiled spring and coil and do it myself. Has anybody done such a thing? It's just frustrating. Nobody knows anything

 

[wore out]

If you want to work on it yourself you will need a manual.

GOOGLE will find you a manual by the model number, probably can even find one to download for FREE.

 

[Butch(OH)]

I've got a question about my Allis Chalmers b I have a 39 with front plow and a 4 8 with woods belly mower both of The magnetos went bad on me. I know it's the coil because if I run the tractor for a while it gets hot and shuts down and fit cools down or if I run cold water on the magneto it'll fire back up so I know that's the problem. But my other problem on both of them is the spring broke so I'm getting zero spark and the spring would be the coiled spring where you would snap. So I bought another magneto from a farmer. Worked great and same thing happened. Coil went bad. It gets hot. It shuts down. I've gone to other places that work on tractors and when I talk to their mechanics it's like I'm speaking Chinese to them. They have zero clue so I was going to attempt to find by the coiled spring and coil and do it myself. Has anybody done such a thing? It's Justin frustrating. Nobody knows

I've got a question about my Allis Chalmers b I have a 39 with front plow and a 4 8 with woods belly mower both of The magnetos went bad on me. I know it's the coil because if I run the tractor for a while it gets hot and shuts down and fit cools down or if I run cold water on the magneto it'll fire back up so I know that's the problem. But my other problem on both of them is the spring broke so I'm getting zero spark and the spring would be the coiled spring where you would snap. So I bought another magneto from a farmer. Worked great and same thing happened. Coil went bad. It gets hot. It shuts down. I've gone to other places that work on tractors and when I talk to their mechanics it's like I'm speaking Chinese to them. They have zero clue so I was going to attempt to find by the coiled spring and coil and do it myself. Has anybody done such a thing? It's just frustrating. Nobody knows anything

Assuming they are FMJ or FMX magnetos(a 39 would not be if OEM) you can go through them yourself. The magnets don't go bad or lose charge. The problem is getting good parts. I tried eBay stuff and it is junk. Search for the John Brillman Company and buy a coil and a tune up kit. Check the caps carefully for carbon tracking and replace If needed. Brillman also has the impulse spring. When you are done you will have the same magneto as if it went to a rebuilder at half the cost. You will need to look up a manual, mainly to tine the rotor gear.

 

[Bob Bancroft]

I've got a question about my Allis Chalmers b I have a 39 with front plow and a 4 8 with woods belly mower both of The magnetos went bad on me. I know it's the coil because if I run the tractor for a while it gets hot and shuts down and fit cools down or if I run cold water on the magneto it'll fire back up so I know that's the problem. But my other problem on both of them is the spring broke so I'm getting zero spark and the spring would be the coiled spring where you would snap. So I bought another magneto from a farmer. Worked great and same thing happened. Coil went bad. It gets hot. It shuts down. I've gone to other places that work on tractors and when I talk to their mechanics it's like I'm speaking Chinese to them. They have zero clue so I was going to attempt to find by the coiled spring and coil and do it myself. Has anybody done such a thing? It's just frustrating. Nobody knows anything

Also the dogs and the pins for the impulse coupling wear. You sure don't want to be hand cranking an engine with a bad impulse as the impulse coupling is what retards the spark for cranking. For these and reasons you mention Delco Remy use to offer a magneto replacement kit. It bolted right onto a magneto mount and included a distributor and coil. There are lots of them around on tractors. Probably some on junked tractors.
Your magnetos are certainly rebuildable given some good parts and knowledge. I mention the battery ignition kit as an alternative (as long as the tractor has a battery!)
For what it's worth, on a bitterly cold winter day, the WD45 (battery ignition) was always the better starter than the WD (with magneto).

 

[Anthonypeet]

Thanks for the replies. I would really like to get away from the magneto and change it to the distributor. I was watching some videos that you can take your magneto and turn it into a distributor but I didn't want to try and waste time and money

 

[wore out]

Thanks for the replies. I would really like to get away from the magneto and change it to the distributor. I was watching some videos that you can take your magneto and turn it into a distributor but I didn't want to try and waste time and money

It is EASY to make a mag into a battery ignition system, HOWEVER, the impulse needs to be functional as it retards the spark timing for cranking, then allows timing to go immediately to running advance as the engine catches.

 

[teddy52food]

I work on mags as a hobby. I have the proper testers that take the guess work out of it. Also can charge up a weak magnet. A condenser can fail too when it gets hot. I think I may have that spring in my collection of used parts. Let me know. OK?

 

[mdm1]

Do a search for Rachel magneto rebuild video. She will walk you through it. I just bought an impulse coupler for a FMJ mag on one of my B's on ebay. Guy bought out on old shop. About half the price of any other NOS coupler.