i got a OS MAX .21 RG just had the sleeve pinched and installed new o-rings in carb and havent touched it since..got a new mod engine so i was keeping this as a backup engine..since our season is over i will sell it if you want it..i have all my sleeves pinched by RAYARACING.COM he is a super guy to deal with and has come through for me many times before..$90 shipped and it will have more compression than a new one, longer run time too..brand new they are about $115