well I just traded my YFZ450 for it and took the head off of it and didn't like what I seen there is alot of piston side to side play and it's a 2003 still at stock bore I'd like a little more compression and to refreshin it up. I don't know what kind of compression is normal for the banshee I know I could crank it over by hand very easy I just got a good deal on a wiseco piston /gasket kit for $199 .00 I want to get a mod Quad head but all the domes I'm finding are for a 65.5 bore