854070 Mercruiser GUIDE-VALVE

This engine uses high voltage to control the fuel injectors.Disconnect electronic fuel injector enable circuit connector to prevent personal injury.Do not come in contact with the fuel injector terminals while the engine is running.
Note: Valve lash is measured between the rocker arm and the bridge for the inlet valves. Valve lash is measured between the rocker arm and the valve stem for the exhaust valve. All of the clearance measurements and the adjustments must be made with the engine stopped. The valves must be fully closed. Valve Lash Check
Table 1
Inlet Valves Exhaust Valves
Valve Lash Check (Stopped Engine) 0.38 0.08 mm (0.0150 0.0031 inch) 0.64 0.08 mm (0.0252 0.0031 inch)
TC Compression Stroke 1-2-4 1-3-5
TC Exhaust Stroke(1) 3-5-6 2-4-6
Firing Order 1-5-3-6-2-4(2)
(1) 360° from TC compression stroke
(2) The No. 1 cylinder is at the front of the engine.An adjustment is not necessary if the measurement of the valve lash is in the acceptable range. Adjust the valve lash while the engine is stopped. The range is specified in Table 1. If the measurement is not within this range adjustment is necessary. See Testing And Adjusting, "Valve Lash And Valve Bridge Adjustment".
Illustration 1 g01193938
Cylinder and Valve location
(A) Exhaust valves
(B) Inlet valves Valve Lash and Valve Bridge Adjustment
Illustration 2 g01229786
(1) Exhaust rocker arm
(2) Inlet valve bridge
(3) Rocker arm adjustment screw locknut for the exhaust rocker arm
(4) Rocker arm adjustment screw for the exhaust rocker arm
Table 2
Valve Lash
Valves Dimension of Gauge
Inlet 0.38 0.08 mm (0.0150 0.0031 inch)
Exhaust 0.64 0.08 mm (0.0252 0.0031 inch) Adjust the valve lash while the engine is stopped. Use the following procedure to adjust the valves:
Put the No. 1 piston at the top center position on the compression stroke. Refer to Testing and Adjusting, "Finding Top Center Position for No. 1 Piston".
Table 3
TC Compression Stroke Inlet Valves Exhaust Valves
Valve Lash 0.38 0.08 mm (0.0150 0.0031 inch) 0.64 0.08 mm (0.0252 0.0031 inch)
Cylinders 1-2-4 1-3-5
Adjust the valve lash according to Table 3.
Lightly tap the rocker arm at the top of the adjustment screw with a soft mallet. This will ensure that the lifter roller seats against the camshaft's base circle.
Loosen the adjustment locknut.
Place the appropriate feeler gauge between rocker arm and the valve bridge. Then, turn the adjustment screw in a clockwise direction. Slide the feeler gauge between the rocker arm and the valve bridge. Continue turning the adjustment screw until a slight drag is felt on the feeler gauge. Remove the feeler gauge.
Tighten the adjustment locknut to a torque of 30 7 N m (22 5 lb ft). Do not allow the adjustment screw to turn while you are tightening the adjustment locknut. Recheck the valve lash after tightening the adjustment locknut.
Remove the timing bolt and turn the flywheel by 360 degrees in the direction of engine rotation. This will put the No. 6 piston at the top center position on the compression stroke. Install the timing bolt in the flywheel.
Table 4
TC Exhaust Stroke(1) Inlet Valves Exhaust Valves
Valve Lash 0.38 0.08 mm (0.0150 0.0031 inch) 0.64 0.08 mm (0.0252 0.0031 inch)
Cylinders 3-5-6 2-4-6
(1) Position for No. 1 cylinder
Adjust the valve lash according to Table 4.
Lightly tap the rocker arm at the top of the adjustment screw with a soft mallet. This will ensure that the lifter roller seats against the camshaft's base circle.
Loosen the adjustment locknut.
Place the appropriate feeler gauge between rocker arm and the valve bridge. Then, turn the adjustment screw in a clockwise direction. Slide the feeler gauge between the rocker arm and the valve bridge. Con