first thing to change is the Main Jet from 77.5 to 87.5 no need to change Exhaust . Front sprocet drop from 14 teeth to 13 teeth . The rear change from 47 teeth standard to as low as 40 teeth .This will increase the top speed to 65 MPH but more importantly this will increase your up hill speed and keep power when in head winds . the motorcycle will improve dramaticlay in head winds and up hill cruse at 65 to 70 mph