Donny Emler Jr 2017 Bike build. Take peek at the latest FMF build as Donny teamed up with Rocky Mountain ATVMC to turn out the ultimate Off-RoadMotocross friendly bike. Utilizing Husqvarna’s FX450 platform, Donny had a jump start on what is typically wanted for off-road. Check out the list of parts below and watch the full length video put together by Rocky Mountain to see all the exclusive details to this build.