DanB53
Bronze Member
I just bought a McCormick-Deereing W4 that has 6v generator, wiring, voltage regulator and battery but a 12v coil. I haven't got it running it yet but before I do should I change coil to a 6v or does it matter?
Adding resistance would be counter intuitive. 12V coils actually run on about 6 volts so you are about right. The ballast resistor / resistor wire in series with the coil reduces the voltage. When starting, the battery voltage is low due to the heavy current draw, so the ballast / resistor wire is bypassed during starting to supply the coil with the full battery voltage. If it starts ok, don't worry about it. If the spark is weak and there is a ballast or resistor wire, replacing it with a piece of wire will help.Why don't you put a resistor in there. I think that's how Larrys Wd Allis was hooked up. A resistor like the one on my hit and miss engine is what he used. Running with the 12 volt coil will probably have to much resistance and make the engine have a weak spark.
Adding resistance would be counter intuitive. 12V coils actually run on about 6 volts so you are about right. The ballast resistor / resistor wire in series with the coil reduces the voltage. When starting, the battery voltage is low due to the heavy current draw, so the ballast / resistor wire is bypassed during starting to supply the coil with the full battery voltage. If it starts ok, don't worry about it. If the spark is weak and there is a ballast or resistor wire, replacing it with a piece of wire will help.
what are we suposed to be seeing.. it's a pretty common site to see a ign coil seting like that near a dizzy... nothing too special about it???