Alright my brother has a banshee running a 66mm piston, 17cc domes and a wiseco piston with an mx port, lightened flywheel and 34mm carbs. We know the carbs are too big they were bought for his original plans and his motor guy screwed him but his compression also seemed a little low for where we live and what he's got at a 165psi. We also found his HD clutch and springs are crap already too after three dunes trips. So my advice to him was to find some 30mm carbs or maybe even 28s and get a lockout. I just don't see the power there considering my bike just got a fresh top-end with a stock bore and I also had the crank trued with no port I can hang next to him off the line and pull him top end. I also have 17cc domes on mine. We both figured he should be able to tap me all day. Any advice would be appreciated.