How do I adjust the valves on my 2003 Yamaha Warrior YFM 350X?

First you need to remove everything that covers your valve covers(gas tank etc.) remove the intake valve cover,and the rotor nut and timing plug.set the engine a t.d.c.(top dead center)fit a socket onto the rotor nut and turn it counterclockwise until the"I" mark appears align it with the index mark in the timing hole.use a flat feeler gauge between the top of the valve and the adjuster.loosen the locknut and turn the adjuster just until you feel resistance on the feeler guage.hold the adjuster and tighten the lock nut down.i can not tell you the min.clearance spec to your quad since i have a 660 raptor.try using the smallest clearance number.