My 08 would do 48 prior to putting in an aftermarket cdi, then it would do 52.
Now before you get to worked up, what size tires? windshield? any load? A lot of factors come into the top speed.
A clutch kit generally won't get you any top speed, they are more for gaining back what you lose for over size tires and such.
Airdam can machine your clutch sheaves for more top speed though, but the 650 can only do so much without engine mods.
2010 Prowler XTZ 1000-
27" Grim Reaper Tires/Home Made Roof/Arctic Cat Mirror/Quadboss Folding Windshield w/ home made support bar/LED Tail-Brake lights//Venom 4000 lb Winch/Amsteel synthetic line/Home Made Doors/Custom Adjustable Seats/Custom Oh Crap bar for passenger/Tonneau Cover/Fat Max storage Box in bed
Tiger Tail Towing system