I had a 1989 FJ1200 I bought new. It would go 65 mph in 1st gear and 165 mph in 5th gear. The only reason I didn't ride it faster was at 165 the engine rpm was in the yellow on the tachometer. The bike was still accelerating strongly at 165 and I truly believe it would have gone 180 with another tooth on the countershaft sprocket.
fast
if it is a Yamaha wolverine 450 it will go 61mph
a Yamaha blaster can go around 75-80
155mph
Not that fast but about 50 with no upgrades
the Yamaha ttr125 goes about 50 to 55 mph
about 70mph
70mph
About 75 mph
700mph
2099
about 70 to 80mph