12077 Mercruiser SEAL

Table 1
Valve Lash Setting: Engine Stopped
Valves Gauge Dimension
Inlet 0.50 0.08 mm (0.020 0.003 inch)
Exhaust 1.00 0.08 mm (0.040 0.003 inch) Introduction
Use this procedure for adjusting the valve lash.Required Tools
Table 2
Item Qty Part Number Part Name
T1 1 147-2059 Torque Wrench
T2 1 147-2060 Wrench
T3 1 147-5482 Valve Lash Gauge Gp
T3a 1 145-5191 Gauge Support As
T3b 1 147-2056 Dial Indicator
T3c 1 147-2057 Indicator Contact Point
T3d 1 147-2058 Indicator Extension
T3e 1 147-5536 Indicator Contact Point
T3f 1 148-7211 Bridge Nut Socket
T4 1 581-9600 Bar
Illustration 1 g06429093
(T1) 147-2059 contrTorque Wrench
(T2) 147-2060 Wrench
(T3a) 145-5191 Gauge Support As
(T3b) 147-2056 Dial Indicator
(T3c) 147-2057 Indicator Contact PointOptional Tools
Table 3
Item Qty Part Number Part Name
T4 1 147-5537 Dial Indicator (Metric)
T5 1 570-4815 Tool Gp (3500 Valve Lash Feeler Gage)
T5a 1 570-4816 Valve Lash Feeler Gage
T5b 1 570-4817 Valve Lash Feeler Gage Valve Lash Adjust Preparation
Ensure that the number 1 piston is at the top center position. The valves must be fully closed when the adjustment is made. Refer to Testing and Adjusting, "Finding the Top Center Position for the No. 1 Piston".
The number 1 piston must be at the top center position of the correct stroke. Adjust the valves according to the chart: Refer to Testing and Adjusting, "Crankshaft Positions for Valve Lash Setting".Valve Lash Check and Adjust (Dial Indicator)
Tap each rocker arm on the top of the adjustment screw before you make any adjustments. Use a soft hammer. Make sure that the lifter roller is seated against the base circle of the camshaft.
Illustration 2 g06429229
(T3a) 145-5191 Gauge Support
(T3b) 147-2056 Dial Indicator
(T3c) 147-2057 Indicator Contact Point
Install Tooling (T3) onto the appropriate rocker arm assembly:
Install Tooling (T3c) into Tooling (T3b) or Tooling (T4).
Attach Tooling (T3b) or Tooling (T4) to Tooling (T3a).
Install Tooling (T3a) into the rear bolt hole on the valve cover base.
Illustration 3 g06429235
(T1) 147-2059 Torque Wrench
(T2) 147-2060 Wrench
Illustration 4 g06429239
(T1) 147-2059 Torque Wrench
(T2) 147-2060 Wrench
Install Tooling (T1) and (T2) on the nut of the rocker arm. Use Tooling (T1) and (T2), move the rocker assembly upward and move the rocker arm assembly downward. Move the rocker assembly several times. The oil film is removed to get a true zero reading on the dial indicator.
Apply upward pressure to the front of the rocker assembly with Tooling (T1) and (T2). Set Tooling (T3c) to zero. The weight of the Tooling (T1) allows the valve lash to be read. Do not apply any pressure on Tooling (T1).
Adjust the valve lash on the appropriate valves:
Loosen the adjustment locknut.
Turn the adjustment screw until the valve lash is set to specifications.
Tighten the nut for the adjustment screw. Tooling (T1) is preset to the torque that is required.Note: Do not allow the adjustment screw to turn while tightening the locknut.Torque adjustment locknut ... 70 15 N m (50 11 lb ft)
Check the adjustment again.Valve Lash Check and Adjust (Feeler Gage)
Tap each rocker arm on the top of the adjustment screw before you make any adjustments. Use a soft hammer. Make sure