if you get the manual via this forum, i'm sure there is the revs vs speed for each gear mentioned.
I've overgeared mine so its 5500rpm to 60mph usually its 6k to 60mph/9.8k to 100mph (yes i've seen that on my bike)
if your still not happy, then you will need to strip down the right hand clutch cover and check the quadrant and pawl is free to move the gears. you will be able to see this happening if someone changes gear (engine not running as you will have no oil in the engine, did i mention you need to drain the oil? ) it's obvious when you see it happening just sounds complicated.
drewps