Aren't those the the total insulation outside diameter?Thanks for your responses - what prompted the question was when I looked on GSsparks website for plug leads I noticed they had 5,7,8,9 mm copper core thickness although the 7 mm one looks by far the most common... I have a repeat with six volt magneto so want to make the best leads I can. Cheers
Ahh yes thanks, presumably the core is standard Thickness, 7mm etc would be quite a size....Aren't those the the total insulation outside diameter?
The spark plug wire you want must fit through the caps on the pickup, see pic below. measure yours and you'll know what to buy.