Here's my first post and thought you'd be interested in the dyno results from the 426. It's a 2001 Uk bike with yz pipe, yz timed exhaust cam, air box lid off and on supermotos. Engine only done 1000 miles since top end rebuild after valve dropped (i think as so wrecked hard to tell cause?) so fresh internals -piston, valves/guides, barrel re-plated, head repaired cost over 1500 pounds here in uk to put right. Enough poke for third gear wheelies and just over 100mph top end with current sprockets.