877829T01 Mercury MANIFOLD, Intake

Valve Lash Setting
The valve lash setting is for a cold engine.Valve lash settingInlet valve ... 0.2 0.05 mm (0.008 0.0020 inch)Exhaust valve ... 0.2 0.05 mm (0.008 0.0020 inch)Valve Lash Adjustment
If the valve lash requires adjustment several times in a short time period, excessive wear exists in a different part of the engine. Repair the problem to prevent more damage to the engine.Not enough valve lash can be the cause of rapid wear of the camshaft and valve lifters. Not enough valve lash can indicate that the seats for the valves are worn.Valves become worn due to the following causes:
Incorrect operation of fuel injectors
Excessive dirt and oil are present on the filters for the inlet air.
Incorrect fuel settings on the fuel injection pump.
The load capacity of the engine is frequently exceeded.Too much valve lash can cause broken valve stems, springs, and spring retainers. Too much valve lash can be an indication of the following problems:
Worn camshaft and valve lifters
Worn rocker arms
Bent pushrods
Broken socket on the upper end of a pushrod
Loose adjustment screw for the valve lashIf the camshaft and valve lifters show rapid wear, look for fuel in the lubrication oil or dirty lubrication oil as a possible cause.The valve lash is measured between the top of the valve stem and the rocker arm lever.Note: No. 1 cylinder is at the front of the engine.Remove the Valve Mechanism Cover. Refer to Disassembly and Assembly, "Valve Mechanism Cover - Remove and Install".Note: During the inspection and adjustment of the valve lash, the front housing must be installed.
Accidental engine starting can cause injury or death to personnel.To prevent accidental engine starting, turn the ignition switch to the OFF position, place a do not operate tag at the ignition switch location and disconnect and tape the electrical connection to the stop solenoid that is located on the fuel injection pump.
Valve Lash Adjustment for Two Cylinder Engines
Illustration 1 g01107989
Setting the valve lash
(1) Feeler gauge
(2) Adjustment screw
Illustration 2 g01879993
Typical Example
Rotate the crankshaft in a clockwise direction until the exhaust valve for No. 1 cylinder is nearly closed and the inlet valve for No. 1 cylinder is starting to open.
Rotate the crankshaft in a clockwise direction through an extra 360 degrees and align the timing mark (4) on the crankshaft pulley with the "TOP" mark (3) on the timing case. No. 1 cylinder is now on the firing cycle.The valve lash can now be inspected and adjusted on No. 1 cylinder.
Loosen the valve adjustment screw locknut that is on adjustment screw (2).
Place the appropriate feeler gauge (1) between the rocker arm and the valve. Turn adjustment screw (2) while the valve adjustment screw locknut is being held from turning.
Adjust the valve lash until the correct specification is achieved.
After each adjustment, tighten the valve adjustment screw locknut while adjustment screw (2) is being held from turning.
Rotate the engine crankshaft in a clockwise direction until the exhaust valve for No. 2 cylinder is nearly closed and the inlet valve for No. 2 cylinder is starting to open.
Rotate the crankshaft in a clockwise direction through an extra 360 degrees. No. 2 cylinder is now on the firing cycle.The valve lash can now be inspected and adjusted on No. 2 cylinder.If necessary, repeat Step 2.a through Step 2.d to carry out adjustment.Valve Lash Adjustment for Three Cylinder Engines
Rotate the crankshaft in a clockwise direction until the exhaust valve for No. 1 cylinder is nearly closed and the inlet valve for No. 1 cylinder is starting to open.
The valve lash on the inlet valve of No. 2 cylinder, and the exhaust valve of No. 3 cylinder can now be inspected. If necessary, make adjustment.
Loosen the valve adjustment screw locknut that is on adjustment screw (2).
Place the appropriate feeler gauge (1) between the rocker arm and the valve. Turn adjustment screw (2) while the valve adjustment screw locknut is being held from turning.
Adjust the valve lash until the correct setting is achieved.
After each adjustment, tighten the valve adjustment screw locknut while adjustment screw (2) is being held from turning.
Rotate the crankshaft in a clockwise direction until the exhaust valve for No. 2 cylinder is nearly closed and the inlet valve for No. 2 cylinder is starting to open.
The valve lash on the inlet valve of No. 3 cylinder, and the exhaust valve of No. 1 cylinder can now be inspected. If necessary, make adjustment.To adjust the valve lash, repeat Step 2.a through Step 2.d.
Rotate the crankshaft in a clockwise direction until the exhaust valve for No. 3 cylinder is nearly closed and the inlet valve for No. 3 cylinder is starting to open.
The valve lash on the inlet valve of No. 1 cylinder, and the exhaust valve of No. 2 cylinder can now be inspected. If necessary, make adjustment.To adjust the valve lash, repeat Step 2.a through Step 2.d.