If you run your TW over 55MPH your valves start to float due to the piss-pore Yamaha design of cutting corners and using weak valve springs. I just scattered my engine at 70mph. Broke exhaust rocker, bent valves and trashed the piston. Don't know if Yamaha is gonna warranty the rebuild. HEY YAMAHA, IF IT'S NOT SUPPOSED TO BE RIDDEN OVER 55MPH, LIMIT THE F*****G REVS!