J4 Mag Has Spark but None to Plugs

[AL Farmall Boy]

Had a guy call earlier needing help with a J4 magneto. He said he has replaced his coil, points, condenser, rotor, cap, and has spark coming from mag when spinning it by hand. Said its shocking him. He said he has installed it on the tractor and has even tried it with the kill wire unhooked, but has spark coming out of coil but none to plugs. I told him it has to be either the cap, rotor, or wires. He said he has replaced all of those and I'm not sure what else it could be unless he got bad parts. He is testing the spark to the plugs by holding the plug wire to ground to a local surface (no spark tester).

Am I missing something? Any ideas??

[tmays]

I’d file the points. New points sometimes have a coating on them.

[AL Farmall Boy]

I’d file the points. New points sometimes have a coating on them.

But, he is getting spark enough to shock him when holding the mag and spinning over by hand............

[Dave Downs]

Rotor incorrectly timed?

[tmays]

I’d file the points. New points sometimes have a coating on them.

But, he is getting spark enough to shock him when holding the mag and spinning over by hand............

Should’ve paid more attn. Lol. Could be plug wires or bad plugs. Are you using starter to turn over on the tractor? If so, maybe the mag isn’t snapping at starter speed?

[Waif]

Be sure insulator for points isn't broken or out of position allowing points to ground /short out.

Parts quality matters ; and a bunch of them were changed...
Was the tractor running prior? Did ignition components that worked get saved?
IF a known good condenser exists ; I'd be half tempted to install it.

[Crimson Tim]

Solid copper plug wires? *not* resistor wires, right?

“Holding plug wire to ground” means ~1/4” away from ground, yes? If it’s actually touching, it will just short and no spark will be visible.

[AL Farmall Boy]

I’d file the points. New points sometimes have a coating on them.

But, he is getting spark enough to shock him when holding the mag and spinning over by hand............

Should’ve paid more attn. Lol. Could be plug wires or bad plugs. Are you using starter to turn over on the tractor? If so, maybe the mag isn’t snapping at starter speed?

The guy was using the starter. I heard it snapping as he said it was too.

[AL Farmall Boy]

Thanks for the suggestions. I will pass along to him and maybe he'll get it going.

[KETCHAM]

if its impulsating.....condenser needs checked....seen them bad out of the box,many times...coating on points another good point.....cooper wires fore sure ,though I had pretty sillvcone ones that worked fine..they copper now...report what made it good so we know!!!!