The 2008 YZF-R6 was the first 600 to break the 170mph barrier, achieving a top tested speed of 172.34mph stock (A little over 277km/h).
50
With a good rider and excellent road conditions the Yamaha YZF-R1 can do a 0-60mph time of about 2.5 seconds.
Over 140 MPH although I've never tried to push it all the way. I'm sure it would do 150 MPH.
fast
if it is a Yamaha wolverine 450 it will go 61mph
a Yamaha blaster can go around 75-80
155mph
Stock straight off the line would prolly go 60-70 mph but if tuned it can go faster easily.
Not that fast but about 50 with no upgrades
very slow the rmz,yzf,kxf,sxfwill beat it easy
the Yamaha ttr125 goes about 50 to 55 mph
About 75 mph