Only use the red one if you also plan to pinstripe the cap with some “Von Dutch” style artwork.
Thinking of ways to minimize the ugly here. I have read/heard somewhere that you can use these with a cap that does NOT include the coil, and then run a traditional round coil. Is that true? And if so, which cap would that be?
Speedway says these are incompatible with generator charging systems. Input voltage not stable enough at low rpm? Would that be the reason?
