YEAAAAAAAAAAAAAAAAAAAH!
i just got my bike put together about 4:30 last night, and had just enough time to try it out running it down the alley a couple of times. WOAH!!! stepping up from a CRF 150, that thing HAULS!!!
we ran it for a little while, and didn't seem to have any problems shifting. many times we went through all the gears and it ran like a champ. have all you guyes all tried just taking it all apart (transmission, of course) and putting it back together so all the bolts are for sure tightened? if you do and have trouble putting it back together and dont have the manual (like us) just go to the kawasaki web sight, motorcycles, off road, select moddel, KDX 200 (there is no KDX 220), accessories, put in year of bike, and then parts diagrams.
If so, just try a few different transmission oils. The owner of mine had ran one type which most likely caused it to have shifting problems, and we switched to what we usually run in our other bikes and it runs fine.
I'm goona' take it out later tonight when my dad gets off work. we're going riding on Colville Mountain to try it out and test it's hillclimbing skills.
Oh, and by the way, i had gotten it wrong. it's a 2000, not a 2003. my bad.