Hello,

I have a Cat d4 from the thirties....serial number 4g4637w. It has a Eisemann magneto model RC 2H but I've got no spark.... oh this is for the pony motor.... I had spark last fall when we parked it but not now. I went into the mag today and cleaned pts, even though they looked good... no spark.... looked for sparking at pts no spark.... any thoughts? I've been told condenser.... I even turned it over w/ a drill stuck into the input shaft in the middle of the pull start pulley/flywheel. I'm thinking pts and condersor,,,,, could it be in the coil and if so how does one test the coil and condenser... with an ohm meter? anybody know the values involved..... like to keep it stock if it is as old as they say..... thanks in advance... Doug Horvath,,,, here in Oregon where the trees are pretty tall... lol...

Coil should read about 6300 ohms to be good. Condenser 0.24 micro farads.

Hi,
maybe try disconnecting the Mag Switch ground wire and see if the switch/wire is faulty.
Cheers,
Eddie B.

not sure how to measure for farads..... is there a chance the magneto is not magnetized,,, I see a lot of videos on YT that show folks magnetizing their magnetos... ouch.... how bout using a auto coil and condenser powered by a twelve volt cordless drill battery and using the stock pts and the rest of the distributor sending a coil wire through the bottom of the mag and attacing to the copper contact inside....
thanks for all the help,,,, I've worked on lots of equip but never antique stuff... Doug

"Old wrote:

Coil should read about 6300 ohms to be good. Condenser 0.24 micro farads.

You can take a condenser, put it across the posts on a battery for a few seconds to charge, then fold the wire back onto the can(body) to jump a stored spark. Works best in the shade or a dim room! File the points and spin the mag while holding your finger against the center contact, If you get a shock you know its good! I usually get some smart aleck know it all to help with this test!

"drujinin" wrote:

You can take a condenser, put it across the posts on a battery for a few seconds to charge, then fold the wire back onto the can(body) to jump a stored spark. Works best in the shade or a dim room! File the points and spin the mag while holding your finger against the center contact, If you get a shock you know its good! I usually get some smart aleck know it all to help with this test!

now that is funny..... by good do you mean the mag as a whole or the coil.... I'm going to test the coil now and the condenser also if they are good the only thing left if the coil ...... so here we go.... thank you.... Doug

That rating on the condenser/capacitor is pretty low, I don't think you'll get a noticeable spark out of it. Let us know if you do. Any good multimeter should have a capacitance measuring capability.

"Old wrote:

Coil should read about 6300 ohms to be good. Condenser 0.24 micro farads.

One more thing,,, when checking a coil are we testing between the wire and the small tab that acts as a contact from coil to cap? and the wires are all connected to the condenser incl from pts , from coil and from kill switch... correct me if I'm wrong ,, thank you,,,, Doug

Lift the two leads coming off the coil and get a reading. One is the ground to case the other is hot. The leads need to be lifted/disconnected to get a good reading.