Hi, Guys and gals, On my 79 iron my coil is mounted under the fuel tank. It has been converted to points and condenser. The two "ports" for the spark plug wires face left. Now, the spark plug wire from the front "port" goes to the rear cylinder and the spark plug wire from the rear "port" goes to the front cylinder. I can't find any thing in the service manual showing me the proper routing of the wires from coil to plugs. Will engine run either way, does it matter which wire goes where. If so can somebody give me the correct way the wires should be in relation to the + and - 0n the coil. Or what ever. Thanks. Ride safe.

 

Both plugs fire at the same time, every time so it does not matter which wire goes to which plug. It's called single fire ignition.

I am pretty sure your bike started out with points.

Pat

 

Yes, as Pat stated on the plug wires. They both fire at the same time so I'm prett sure it makes no difference. As for the two small 14 gauge wires, the - wire runs to the points and the + wire runs to an ignition switched 12 volt source. At least that's how it is on my 73.
Pretty sure its the same on a 79? ... Mick?

 

+1 on hog4u

 

Thanks everybody, i did find a pic in the manual in clutch adjustment you can see in that pic the front plug wire goes in the front port. (has nothing to do with clutch I just noticed the wires). The bike runs ok, I was just wondering because on other posts I have read , while you are adjusting the points the small lobe is #1 cyl. But if both wires fire at the same time with the same hot spark, wire location dosen't matter. ( I think ) Ride safe.

 

It is called dual fire or wasted spark ignition. Single fire ignitions fire only one plug at a time.

1979 did originally have an electronic control module. Not the same as full electronic ignition. About the only place you can get info on it is in the factory manual.

 

Single fire only fires on the power stroke,dual fires both exhaust and power strokes, does it not? both plugs fire same time either single or dual fire?

 

Dual fire or wasted spark ignition is the traditional Harley Davidson ignition. It fires both plugs at the same time every time. The wasted spark is in the exhaust stroke of the other cylinder. I believe that all current HDs are single fire, and have been for a few or several years - but i do not know.

There may be unburned fuel in that other cylinder which would then be ignited by this spark, causing the engine to somewhat work against itself. I do not know how significant this is, but many believe it is significant.

The CraneCams Hi-4 and Ultima ignitions are examples of single fire ignitions [although the Ultima can be run in either mode]. They fire only the plug in the cylinder on the compression stroke. They essentially need two separate coils, one for each cylinder. The apparent single coil supplied with these ignitions is actually two coils bundled into one package.

Single fire engines idle and accelerate more smoothly.

 

ah.. got it. Was a bit confusing. thanks for the clarification Mick !

 

+1 what he said.