MerCruiser 305 CID (5.0L) Service Manual page 237

SERVICE MANUAL NUMBER 24
IMPORTANT: Use piston ring expander (91-24697) for compression ring installation.
Installation
IMPORTANT: Cylinder bores must be clean before piston installation. Clean with a
light honing, as necessary. Then clean with hot water and detergent wash. After
cleaning, swab bores several times with light engine oil and clean cloth, then wipe
with a clean dry cloth.
1. Lubricate connecting rod bearings.
2. Install connecting rod bearings in rods and rod caps.
3. Lightly coat pistons, rings and cylinder walls with light engine oil.
4. With bearing caps removed, install connecting rod bolt guide 3/8-24 (J-5239) on con-
IMPORTANT: Be sure ring gaps are properly positioned as shown.
Ring Gap Location
5. Install each connecting rod and piston assembly in its respective bore with connecting
6. Use piston ring compressor to compress rings.
7. Guide connecting rod into place on crankshaft journal with connecting rod bolt guide.
Index
90-861327--1 OCTOBER 1999
a. Install oil ring spacer in groove and insert anti- rotation tang in oil hole.
b. Hold spacer ends butted and install lower steel oil ring rail with gap properly located.
c. Install upper steel oil ring rail with gap properly located.
d. Flex the oil ring assembly to make sure ring is free. If binding occurs at any point,
the cause should be determined. If binding is caused by ring groove, remove by
dressing groove with a fine cut file. If binding is caused by a distorted ring, use a new
ring.
e. Using ring expander, install lower compression ring with marked side up.
f. Using ring expander, install top compression ring with marked side up.
necting rod bolts.
e
b
c
b
1-3-5-7 Cylinders
a - Oil Ring Spacer Gap (Tang in Hole or Slot Within Arc)
b - Oil Ring Rail Gaps
c - 2nd Compression Ring Gap
d - Top Compression Ring Gap
e - Engine Left
f - Engine Front
g - Engine Right
rod bearing tangs toward outside of cylinder block.
Use a hammer handle with light blows to install piston into bore.
f
b
c
a
d
b
2-4-6-8 Cylinders
5.0l / 305 cid / 5.7l / 350 cid ENGINES
g
a
d
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