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Valve Adjustment Procedures
Notes
These engines are equipped with hydraulic valve lifters. No adjustment is necessary. However, if valve train is excessively noisy, readjust valves as outlined below.
On some engines, a nylon retainer is used to retain the rocker arm. No provision for adjustment is provided.
INITIAL ADJUSTMENT
Rotate crankshaft until mark on torsional damper aligns with center or ``O'' mark on timing tab, attached to crankcase front cover, and piston of No. 1 cylinder is at top dead center of compression stroke. This may be determined by placing fingers on the valves for No. 1 cylinder as timing mark on damper nears the ``O'' mark on front cover. If valves do not move, engine is in the No. 1 firing position. If valves move, the engine is in the No. 6 firing position and should be rotated an additional revolution.
With valves in No. 1 firing position, adjust exhaust valves 1, 3, 4 and 8, and intake valves 1, 2, 5 and 7 as described in step 3.
Back out adjusting nut until lash is felt at pushrod, then turn adjusting nut inward until all lash is removed. When all lash has been removed, turn adjusting nut in additional one turn. Zero lash can be determined by rotating pushrod while turning and adjusting nut.
Rotate crankshaft one revolution, until pointer ``O'' mark and torsional damper mark are aligned. With engine in this position, adjust exhaust valves 2, 5, 6 and 7 and intake valves 3, 4, 6 and 8.
Install rocker arm covers, then start engine and check idle speed and ignition timing.
READJUSTMENT
The following procedure, performed with the engine running, should be done only in case readjustment is required.
After engine has been warmed up to operating temperature, remove valve cover.
With engine running at idle speed, back off valve rocker arm nut until rocker arm starts to clatter.
Turn rocker arm nut down slowly until the clatter just stops. This is the zero lash position.
Turn nut down 1/4 additional turn and pause 10 seconds until engine runs smoothly. Repeat additional 1/4 turns, pausing 10 seconds each time, until nut has been turned down one turn.
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