COP wire size
 

When making your own harness, what gauge wire should I use? Going on 1.6l, soldering the wires on the ignitor pins. Should I use 18g for trigger and tach wires and 14g for power and ground? Or just use the same gauge throughout? Thanks.

I used 16gauge throughout. It works fine.

Also how are we making those 2/4 wire junctions? Just solder and heat shrink or do they make a special connector? Like the ground for instance, you have one wire coming from the ignitor, then it splits to each coil ground and another ground on the head.

Don't solder wires together. Thats how wires break. I use uninsulated crimp connectors with heatshrink. Shove 2 in one end 1 in the other.

Something like this?

16-14 Gauge Non-Insulated Butt Splices 25 Pieces - Wiring Products

Awesome, thanks!

You guys will likely frown on this but over the last couple of years (and after multiple broken soldered connections in our high vibration environments) I have started stripping, twisting and heat shrinking my connections (i.e. no connectors and no solder) wherever it is physically possible. Since starting this I have experienced no joint failures.

Just my 2c YMMV.