Trev,it is going to be just a huge waste of your hard earned money if you buy those. You will not increase your engine output one iota. Some of the guys that put them on claim their bike runs smoother, that is a lot of money to have your bike run smoother. I was not aware these bike run ruff to begin with. You only need enought spark to light the fuel mixture, any additional voltage is not going to do anything. These are not high compression engines nor are they very high performance. That coil/wires are not going to make em that way either. Vegas