I have a yamaha ct2 175 thats been heavly modified, the bike runs great & is ridiculously fast for a old 175. I cant keep clutches in it, I am on 3rd clutch 2 used and one new, I have tried stiffer springs and differnt trans oil, I dont use clutch to shift and never fan it. It starts to slip in higher gears when it hits the power band. Any help would be appreciated.