My buddy has a 2009 YZ450F and his kick start arm keeps breaking right at the pivot knuckle. Here is a pic of his sixth one. After the third, Yamaha stopped giving him new ones. So here is his routine and how they break. Bike starts cold as usual. No problems. Then, when it's warm, and he is as far away from the truck as possible, he stops to take in the view. When he goes to start the bike and pulls in the hot start level, he says he gets a compression type kick back and wham, that small piece flies off. Now the kick starter is useless. That little knuckle keeps the starter from flipping back towards that back of the bike. Can this starter be swampped out with another year/model? Any ideas?