2008 Yamaha Raptor 250SE / 250SE2 Factory Service Manual, Page 71Get this manual
ADJUSTING THE VALVE CLEARANCE ADJUSTING THE ENGINE IDLING SPEED
dMeasure the valve clearance againeIf the valve clearance is still out of specification, repeat all of the valve clearance adjustment steps until the specified clearance is obtained6Install: all removed parts NOTE: For installation, reverse the removal procedure