need help.. ?!?!

[gohstmofo6696]

ok so on my KX250 i was taking her up and down the street to test me new exhaust gaskets and those where fine, but where the problem comes in is my trans. it would shift into first and second with NO problems but when it comes to third, i click up from second and the lever only goes half way up and goes into nutral.. even when its not running it would only go half way after second... can anybody help a fella out? i have no idea what is wrong and what i need, thnx alot for your time.:ermm:
-steve