ADVANCED AVIATION FORWARD AREA REFUELING SYSTEM MODEL M100A1
ADJUST ENGINE INTAKE AND EXHAUST VALVES
This procedure may be performed with the engine module mounted in the pump-engine module or removed to a workbench,
as desired. The procedure applies to either cylinder head.
Tool Kit, General Mechanics
Remove the three socket head screws (1) that secure each valve cover (2). Remove valve cover and gasket (3) from each
cylinder head. Discard gaskets (3).
Lower pulley guard.
To adjust valves, piston must be at TDC on the compression stroke.
While holding decompression lever (4) in engaged position, rotate crankshaft (5) until intake valve (6) opens and closes.
Continue to rotate to align timing mark (7) with indicator on shroud (8). Piston should be at TDC on the compression
Check intake valve clearance for 0.006 in. (0.15 mm) gap. Perform the following steps if adjustment is necessary. If
valve clearance is satisfactory, repeat procedure for exhaust valve (9).
Loosen intake valve push rod retaining nut (10).
Turn push rod adjusting screw (11) to adjust intake valve (6) gap to 0.006 in. (0.15 mm).
Hold adjusting screw (11) in position and tighten push rod retaining nut (10).
Check valve clearance to ensure gap remains at 0.006 in. (0.15 mm). If gap has changed, repeat adjustment procedure.
Repeat procedure for exhaust valve (9).
10. Repeat entire procedure for both valves in other cylinder head.
11. Use gasket (3) and three socket head screws (1) to install valve covers (2).