ARMY TM 9-2815-257-24 AIR FORCE TO 38G1-128-2 MARINE CORPS TM 10155A/2815-24/3 3-20   3-15.  ROCKER ARM ASSEMBLY MAINTENANCE This task covers head cover removal, rocker arm / valve clearance adjustment, and head cover installation. INITIAL SETUP Tools: Equipment Condition: Tool Kit, General Mechanic’s Automotive Engine cool (Item 2, App. B, Sect. III) A.    HEAD COVER REMOVAL. Remove head cover (1, Figure 3-5) from cylinder   head  (2)  by  removing  bolts  (3).    Remove  cover gasket (4) only if replacement is required. B.    VALVE CLEARANCE ADJUSTMENT. 1. Remove flywheel housing and recoil starter as an assembly (Para. 3-13). 2. Rotate flywheel in the clockwise direction until T mark on flywheel match V mark on cylinder body fin.  This is the top dead center (TDC) position.   Intake   and   exhaust   valves   will   be   in   closed position. 3. Using  a  feeler  gauge,  check  rocker  arm  to valve clearance (Figure 3-6).  Clearance shall be 0.0039 to 0.0059 inch (0.10 to 0.15 mm).  Drag on feeler gauge    when    passing    through    gap    shall    be minimal. 4. If  adjustment  is  required,  loosen  lock  nut  and rotate    adjusting    screw    clockwise    /    counter- clockwise to expand / reduce gap.  Tighten lock nut and recheck clearance. 5. Repeat  steps  3  and  4  until  proper  clearance  is attained. Figure 3-5.  Head Cover Removal