1987-2009 Yamaha ATV YFM350X Warrior Raptor Service Manual, Page 46Get this manual
VALVE CLEARANCE ADJUSTMENT SPARK PLUG INSPECTION
Measure the valve clearance If the valve clearance is incorrect, repeat above steps until the specified clearance is obtained
12Install: Tappet covertexhaust] Tappet covertlntake) NOTE: Install the tappet covers with their ridge facing upward CD Check the o-rings for damageIf damaged, replace