My Cousin's H. . .She's a Runner!

Next, we reinstalled the OLD coil, since we weren't so sure the new one was installed correctly. The old coil was marked "to distributor" and "to ignition." (The new one just has -/+ terminals--which one goes to the distributor and which goes to the ignition? The dealer also said it was a 12v coil but converted to 6v if you put it on a 6v system? Can that be right?) We pulled the coil wire from the distributor cap and put it near the block, then hand-cranked the engine. There was spark.

We pulled each plug, one-by-one, and tested for spark like the coil wire. Every plug was wet--we assume from all the gas we had pulled through when we towed the H the other day. We dried each one, then did the test. All had spark.

We figured it should run now. My cousin cranked her. . .and off she roared--just like she was ready to do 20 acres with that 2-bottom plow! You should have seen the look on his face. He was one happy camper.

We learned a lot--thanks to you fellas.

The starter doesn't seem to work--that's why we towed it in the first place and had to hand-crank it yesterday. Is there a way to troubleshoot that?

Thanks in advance, from this mechanic in training.

John T

The dealer is "wrong as rain" on the coil, however. Heres the deal, if its a 12 volt system, you can use a 6 volt coil simply by adding an external voltage dropping (12 to 6) series Ballast Resistor ahead of the coil after the ignition switch. However, if its a 6 volt tractor, the coil dont somehow automatically mysteriously change and if youre using a 12 volt coil it will still produce some spark, but not as good as if you used the correct 6 volt coil.

A coil is more of a current device then a voltage device and regardless if a 6 or 12 volt unit, it runs and switches about 4 amps of current through its primary winding. To do that, A 6 volt coil has about 1.25 to 2 ohms primary resistance while a 12 volt has more like 2.5 to over 3 ohms. Therefore if you use a 12 volt coil at 6 volts, youre only running about half the normal amps through it as required for a good hot spark. My guess is the spark would be more of a light wimpy yellow then a good hot blue spark under such use.

My advice if youre at 6 volts GET A 6 VOLT COIL.

Myself n Texas Denny n Bob have a hot friendly discussion over on the AC board about coils, go read that if you wanna get cornfused n bored lol

Good Luck n God Bless

John T Nordhoff in Indiana, retired electrical engineer