Coil replacement

[DBLSHOT12]

Hi everyone, I have a few questions about replacing the coil in my 1980 XS650. I purchased an aftermarket coil and would like to know which wire goes to the + side of the new coil, there is a red wire with a white stripe and an orange wire. My thought is the red & white wire should go to the positive side and the orange to the negative side. Looking at the wiring diagram, it shows the R/W wire coming from the on/off switch and the orange wire coming from the exciter, please let me know if I'm correct as I don't want to burn up the new coil. Also does it matter which spark plug wire goes to which plug or do they both fire at the same time? Any help with this is greatly appreciated as I found out the hard way not to disconnect the spark plug with the motor running! Story of my life - If there is a hard way to do something, I will find it!!!

 

[Wingedwheel]

The diagram I’m looking at shows the R/W going to the kill switch and the orange wire going to the igniter.
https://www.xs650.com/attachments/80_xs650g-png.116688/

 

[Jim]

In a dual fire coil such as you're using, it doesn't matter for all practical purposes.
Both primary and secondary sides (coils) are 'floating'. Floating simply means they're not grounded. For the primary, power goes in on one terminal, and is grounded through the igniter box on the other.

The secondary also floats. The HT output goes out one lead, through one plug, across the head to the other plug, and back to the secondary through the other HT lead, completing it's circuit.
So one plug fires from the center electrode out, and the other plug fires from it's ground, across to the center electrode. That means one plug fires positive and the other negative. If you swap the primary leads, the polarity of the plugs reverse... and that's all that happens.
So in the grand scheme of things, there really is no "polarity" to the primary. It'll work just fine either way.

 

[Jim]

Here's an internal diagram of a dual output coil that shows what I was (poorly) trying to explain.
P= primary
S= secondary

 

[DBLSHOT12]

Thanks Jim, That explains a lot, I just didn't want to end up buying another coil because I didn't know what I was doing.
I really appreciate all the help from this forum!

 

[5twins]

If the aftermarket coil you got is Chinese and it goes belly up in a short time, the best and cheapest option for a coil is a used Honda MP08. You can read about them here .....

https://www.xs650.com/threads/honda-mp08-coil.55408/