The stock reeds are 3 separate very thin carbon fiber reeds,connected at the base. The reeds are not sealing anymore, get a RAD VALVE, take the reeds out and polish the inside smooth, install rad valve problem fixed. My 06 cr125 is stock with rad valve,pc silencer,and icat. The cylinder is stock,along with the gearing,and pipe. I,m 175 lbs. in b.suit, it comes off of corners a gear higher than other 125,s and pulls much better than stock, from low to mid.