Need some magneto 101

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   So I bought an allis wd for a song. Guy said he had it running this summer. I met this guy through a customer and the customer gave very good feedback of the owner. So I have to believe that it did truly run this last summer. 

I got it home yesterday and I can't get it to start. I pulled the tractor with about tractor. I can't get even a sputter from it. I'd like to look in the mag but I'm not sure how to go about that. It looks like two caps on it. One small one where the wires hook on and a much bigger ones behind that.

What am I getting into there. I know there is a rotor I'd like to look at and see if it's corroded. 

When I pulled it you could here the impulse clicking. I tried pulling it faster and slower with no luck

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bobkyllo Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 14 Sep 2009 Location: minnesota Points: 1561	Post Options Post Reply Quote bobkyllo Report Post Thanks(0) Quote Reply Topic: Need some magneto 101 Posted: 30 Apr 2017 at 9:22am
	So I bought an allis wd for a song. Guy said he had it running this summer. I met this guy through a customer and the customer gave very good feedback of the owner. So I have to believe that it did truly run this last summer. I got it home yesterday and I can't get it to start. I pulled the tractor with about tractor. I can't get even a sputter from it. I'd like to look in the mag but I'm not sure how to go about that. It looks like two caps on it. One small one where the wires hook on and a much bigger ones behind that. What am I getting into there. I know there is a rotor I'd like to look at and see if it's corroded. When I pulled it you could here the impulse clicking. I tried pulling it faster and slower with no luck

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Steve in NJ Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 12 Sep 2009 Location: Andover, NJ Points: 12016	Post Options Post Reply Quote Steve in NJ Report Post Thanks(0) Quote Reply Posted: 30 Apr 2017 at 9:53am
	Sounds like its equipped with a "J" or "X" series Mag with upper cap, lower cover. If you just want to inspect the rotor, remove the two 8-32 screws from the end cap (where the wires attach) and you'll be able to inspect the rotor. My assumption is that if it was running last summer and not now, the points probably have a film of oxidation over them and the points need a little spritz of TV tuner cleaner or Brakekleen to rid the oxidation killing the spark. Don't use a file. Just a spritz should do the job. Now, when you remove the lower cover, you'll be taking the Mag out of time. How to put the Mag back in time is there is a "C" and and "A" stamped into the fiber timing gear. On the main shaft steel gear, (depending on which Mag you have) there will be either a "dog ear" on one of the steel gear's teeth, or a "Pip" (dimple) mark on the tooth that needs to line up with the fiber gears "C". (do not use the "A") Once both are aligned, the Mag is now back in time. Depending on the Mag lower cover's condition, there usually is a decal inside the lower cover telling you how to align the marks. In a lot of cases, that decal is either gone or mostly worn off from age. Some are lucky to still have the decal, but as long as you know how to time it as I explained, you should be good to go. Also sounds like the impulse is working, so you should be good there.... HTH Steve@B&B
	39'RC, 43'WC, 48'B, 49'G, 50'WF, 65 Big 10, 67'B-110, 75'716H, 2-620's, & a Motorhead wife

bobkyllo Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 14 Sep 2009 Location: minnesota Points: 1561	Post Options Post Reply Quote bobkyllo Report Post Thanks(0) Quote Reply Posted: 30 Apr 2017 at 11:46am
	Thank you Steve. Can I get to the points with out removing the lower cover. If memory serves I think the mag says fmj on it. So I'm guessing it's a Fairbanks Morris model j.

DanD Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 11 Sep 2009 Location: WI Points: 856	Post Options Post Reply Quote DanD Report Post Thanks(0) Quote Reply Posted: 30 Apr 2017 at 3:50pm
	Not to insult your intelligence but have you determined that there is no spark? Did you pull the plugs and check? Were the plugs wet or dry? Do the basic workup before starting exploratory surgery! Edited by DanD - 30 Apr 2017 at 3:50pm

bobkyllo Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 14 Sep 2009 Location: minnesota Points: 1561	Post Options Post Reply Quote bobkyllo Report Post Thanks(0) Quote Reply Posted: 30 Apr 2017 at 5:35pm
	Plugs are not really very wet. They are a bit. I think my spark is well because every now and then I get a small pop. But that's far and few between

DanD Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 11 Sep 2009 Location: WI Points: 856	Post Options Post Reply Quote DanD Report Post Thanks(0) Quote Reply Posted: 30 Apr 2017 at 6:06pm
	My point was just to make sure you actually have no spark before you start disassembling the magneto. Be sure to check out the carburetor. And if you have no spark at least try it with the magneto ground wire unhooked to eliminate a problem with the ground wire or switch. Again just try easy first. Doesn't usually work but always worth a try.

WC7610 Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 11 Sep 2009 Location: Sioux City, IA Points: 764	Post Options Post Reply Quote WC7610 Report Post Thanks(0) Quote Reply Posted: 30 Apr 2017 at 6:39pm
	while turning it over check each wire one by one holding them with a gap between wire and plug to see if they have a spark. Will confirm or eliminate one problem.
	Thanks Most Bad Government has grown out of Too Much Government- Thomas Jefferson

Steve in NJ Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 12 Sep 2009 Location: Andover, NJ Points: 12016	Post Options Post Reply Quote Steve in NJ Report Post Thanks(0) Quote Reply Posted: 30 Apr 2017 at 10:32pm
	Another thing that I forgot to mention in my first post, if the Tractor is equipped with a remote kill switch up near the driver, disconnect it and see if the spark magically appears again. If it does and it starts up, there's your culprit! Bad kill switch.
	39'RC, 43'WC, 48'B, 49'G, 50'WF, 65 Big 10, 67'B-110, 75'716H, 2-620's, & a Motorhead wife

Bill Long Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 12 Sep 2009 Location: Bel Air, MD Points: 4556	Post Options Post Reply Quote Bill Long Report Post Thanks(0) Quote Reply Posted: 01 May 2017 at 8:57am
	Listen closely to what is said above. You are very fortunate to have been given outstanding information from some of our best electrical experts. Good Luck! Bill Long ps: If you do have to get into the mag do not be intimminated. If I can do it I am certain you could. However, do the very basics first before getting into the mag.