Kris Keefer July 7, 2017 Motocross Spending Quality Time With The 2017 Yamaha YZ450F Kris Keefer July 7, 2017 Motocross Kris Keefer has over seventy total hours on the 2017 Yamaha YZ450F and have had no engine failures to date. Check out his mods and updates on the YZ450F here.
