Q: FIRST AND FOREMOST, IS THE 2012 YZ450F BETTER THAN THE 2011 YZ450F? A: That depends on how you define ?better.? It is quieter and the rims are black, but apart from that, the modifications are of the garden-variety type?new mapping, new valving, new muffler and new tires. The 2011 model was a warmed-over 2010 YZ450F, but the 2012 gets more power thanks to an odd combination of slowing it down and speeding it up. Q: WHAT ARE THE MAJOR CHANGES THAT YAMAHA MADE TO THE 2012 YZ450F? A: There aren?t any ma…