Check that the foot shift lever isnt loose, otherwise, I would pop the right side covere off and inspest the external shift mechanism and the outer shift drum for wear. 200x's are a lot of fun and possibly the most versatile and all around best bike for any aplication. Is this your first 200x?
THE 80's RAGE! Currently owns:
81, 85 Yamaha Tri Moto 125
83 Yamaha Tri Moto 200 x2
82,83 Yamaha Tri Moto 175 project
85 Yamaha Tri Z 250
84 Kawasaki Tecate 250
84 Honda ATC 70
85 Honda ATC 350X
84 Honda ATC 250R
(2) 84 Honda ATC 200x
82, 83 Honda ATC 185s
81 ATC 200
Lots of other parts and bikes