I don't think that the advance ignition key is a replacement for the CDI box. I thought the rev limiter was the worst thing about this big thumper. It would just get into a good stride when the limiter would haul it back. I put the RWR CDI Box in and I had a completely different machine. The advance key, I think (IMHO) should enhance the performance of either a stock or modded bike, but certainly won't make the big difference like the CDI box. I'm looking to see if I can bleed a couple more HP from this rock before having to call Knutz for a big bore. I'm in the position these days to spend $10.00, not a couple grand...yet[img]i/expressions/face-icon-small-wink.gif[/img]