Looks like I now can add a blown countershaft seal to the list of problems I've had with my WR450. At the end of my latest ride, heard a strange noise from the rear of the motor. Looked down to see oil gushing out from around the countershaft sprocket. Ordered a new seal and plan on replacing it this weekend but don't know if I've had any engine damage. I think it must have happened just before I stopped for the day since I didn't see much oil on the chain and rear of bike. So far, 3 woodruff key failures and a blown CF seal with less than 1000 miles - not a pretty picture. Anyone else had this problem with the 450 yet or am I the lucky one?