How can I tell the difference between a stock and aftermarket flywheel? My 450 has always felt slow to rev compared to other 450s and Im wondering if the previous owner(XC racer) installed a heavier flywheel. Some of the markings I remember seeing were 11EX and Denso. Does this sound like a stock flywheel? It looks identical to pics Ive seen of stock flywheels but Im not for sure.. Any help?