I just installed a YZ exhaust cam in my 03' WR450 and maybe I am a powerhog but I am not noticing much of a difference. I am currently doing a lot of motocross so I am looking for more snap toward the low/low mid of the powerband. In the mid to upper the bike is great, but it was before the cam upgrade. A rider friend has a 03 YZ450 and a 99 WR400 and told me that is maybe because of the heavy flywheel of the WR450. Does anyone know the weight of a WR450 flywheel compared to a YZ450 flywheel? And any suggestions/solutions to my problem are welcome as well. Thanks.