With YZ timing and an E-Series exhaust (12disks)+ air-box lid removed, I found that I lost much of my bottom end. In the tight and on really steep rocky stuff it isn't much fun. I had to resort to too much clutch abuse. I would love the WR bottom end and YZ mid to top end. Other than flywheel weights are there any other options? Someone told me that a tapered header pipe would make a big difference. Is this true?