PAMCO kits - High output vs Std

mgreaves · Posted: July 15, 2009, 8:23 am Post subject: PAMCO kits - High output vs Std

Hello Pamcopete: I am going to buy your ignition system from Mikes. I have a 77D. Quick question - is the high output unit (green coil) better/more reliable than the standard system with the black coil?

pamcopete · Posted: July 15, 2009, 9:06 am Post subject: Re: PAMCO kits - High output vs Std

mgreaves

Well, good question. You bike will run just fine with either coil. The main difference is the output voltage and what you can do with the higher voltage of the "Green Monster" coil.

The standard coil, which is now Mikes 17-6822, produces a nominal 37K volts and has an excellant spark duration. The longer spark duration means that the initial kernel of flame is larger simply because the mixture is exposed to the spark for a longer period of time. Having a larger initial kernel of flame means that more of the total mixture will be ignited in the very brief time available in the compression stroke. You would use 5K caps and stock plug gap wtih this coil.

The Green Monster" produces 75K volts. So, how would you use this really high voltage? The spark duration of the green coil is not as long as the standard coil, but the higher voltage allows you to use resistor plugs as well as the 5K caps. This arrangement will increase the spark duration because the dissipation of the coils energy is slowed down by the reduced current. So, you end up with a higher voltage (hotter) and a longer spark duration. The higher voltage also allows you to increase the plug gap to, say, .040. Now you have a hotter and longer duration spark with a wider gap which exposes even more of the mixture for that all important initial kernal of flame. The result is a more complete burn of the mixture which improves performance all across the RPM range.

The Green coil will also provide better starts because its output voltage will be almost equal to the standard coil at the low voltage associated with starting.

I tested both coils at 6 volts to simulate a start with a low battery. They each produced something less than half of there full potential voltage.

The higher voltage of the green coil will also "burn" through minor fouling more readily, although neither coil will burn through a really badly fouled plug because those plugs are essentially a short circuit through the carbon accumulation.

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