Cylinder Head; Removal; Cleaning; Inspection - Mercury MerCruiser MCM 454 Mag MPI Service Manual

SERVICE MANUAL NUMBER 23
3. Place valve spring assembly in position with tighter wound coils against spring seat.
IMPORTANT: Valve seal and cap must be assembled as shown before installation.
4. Coat valve stem and new seal with engine oil.
5. Set cap and seal assembly on valve stem. Align valve stem with center of valve seal.
6. Compress valve spring, using valve spring compressor, and install valve locks (grease
7. Install push rods and rocker arm assemblies. Torque to specifications.
8. Install rocker arm cover and torque to 71 lb-in. (8 Nm). Install spark plug and torque to

Cylinder Head

Removal

1. Drain engine cooling system.
2. Remove as outlined:
The head gasket may be holding cylinder head to block. Use care when prying off
cylinder heads. DO NOT damage gasket surfaces. DO NOT drop cylinder heads.
3. Place cylinder head on wooden blocks to prevent damage to gasket surfaces.

Cleaning

1. Clean gasket material and sealer from engine block and cylinder heads.
2. Clean head bolt threads and engine block bolt hole threads, making sure no dirt, old oil

Inspection

1. Inspect sealing surfaces for deep nicks and scratches.
2. Inspect for corrosion around cooling passages.
3. Inspect for cylinder head gasket leakage or corrosion.
Index
90-861326--1 MARCH 1999
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may be used to hold valve locks in place). Slowly release tool to prevent damaging seal.
Make sure valve locks seat properly in valve stem grooves.
15 lb-ft (20 Nm).
a. Exhaust manifolds.
b. Intake manifold.
c. Rocker arm covers.
d. Rocker arm assemblies and push rods (keep in order for reassembly in their original
locations).
e. Any components attached to front or rear of cylinder head.
f. Spark plugs.
g. Head bolts.
or coolant remain.
CAUTION
454 CID (7.4L) / 502 CID (8.2L)
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