WD Magneto Question

Here's the picture. Hal

You can always convert your mag to a distributor
by using an auto type coil if you have battery start on your tractor. You would use the points
that's in the mag as shown in this picture. Hal

• Hobby farm

Or have you left the mag on the tractor all along without disturbing the timing at the impulse coupling?

If turning the coupling by hand, are you hearing the snap of the impulse coupling, which is required to create enough speed to generate a spark.

Are you testing for spark only at the four sparkplug wire terminals? If so, you must have the teeth aligned properly inside, or the spark is not delivered to the terminals by the rotor. What shape is the rotor in?

You had an issue with the grounding terminal. These will sometimes ground to the case of the mag, and you will never generate a spark. You can check this out by measuring the resistance between the end of this ground screw and the mag case. It should be infinite until the grounding strap is pressed down. If you still have a kill wire running to the switch box, is it grounded somewhere?

You can get to the mount for the grounding screw by removing the coil of the mag if you need to renew the internal insulation of the grounding screw (kill switch).

If all else has failed you might have a dead coil. It is easily replaced once you get the two mounting screws on the mag backed out (they can be really tough sometimes).

Did you follow the troubleshooting guide in the manual in the link? If the mag is off the tractor, mount it in a vice and remove the upper cap and rotor. Rotate the impulse couple with pliers and check the copper rod for spark to ground.

Tell us more about what you have checked out. You won't do any damage by removing anything that comes off easily. You probably don't want to remove the impulse coupling & rotor unless you are equipped & knowledgeable.

Take a cotton swab dipped in alcohol and clean those new points several times, then see if you have fire. The coil may be weak from age or the magnets may have lost their magnetism. You can touch them with a flatblade screwdriver and see if they attract that screwdriver with some effort.
Here's an old mag off a twin cylinder garden tractor with weak magnets. Hal

• FMJ Magneto

A magneto generates its own current for the high tension coil and is shut off by grounding the little terminal on the side. There should be a curly flat springy thingy which can be pressed to kill the engine. The WD left the factory with a push-pull switch next to the ammeter. It has one terminal for a wire which runs to the mag terminal, grounds out the mag to stop it.

Often, when a mag failed and needed expensive repair, we sold a Delco-Remy 6 volt replacement distributor which required a 2 terminal switch to supply battery voltage to the distributor.

You need a wire from a switch to the grounding post on the mag so it will ground out the mag so you can stop the engine. Should be one similar to the grounding post that's on this old mag. Hal