Ok i have a 2002 banshee with these mods. cool head with 21cc domes, v-force 2 reeds, weisco pro lites stock bore, timing is advanced 4 degrees and fmf pipes, I am at 500 feet above sea level.. My question is do i need to run more than 93 octane pump gas i just got to ride it today and i'm hearing a slite nock or pinging sound other than the pipes.. I can hear it at idle and it gets louder when its under a load... Am i getin detination from lack of octane or what am i missing?? Thanks Matt