Hey guys, been reading a lot lately about doing the RM piston mod in my 2003 cr125 w/ Eric Gorr 134 kit with mid-top port and 7oz flywheel weight. Eric says the RM piston would make a big difference in the bottom end, and I trust eric completely. The only thing I am wondering is how much will it flatten out my top end? I race harescrambles so I need bottom end, but I would really hate to kill my topend....thats what makes a 125 so fun to ride Bike specs: 2003 cr125 EG 134 BB w/ mid-top port (pump gas) Boyseen rad valve pro circuit pipe/shorty 7oz flywheel weight 12/53 gearing Stock carb/05+ air boot Opened up airbox (10 1/2 holes) So how bad of a hit would my bike take on the top end power and over rev??