Yanmar YM276 Service Manual page 116

Cylinder Block, Liners, Pistons, and Rods
20-103
PISTONS
REMOVAL
It
is not necessary t o remove the engine t o service pistons, rods
and liners. If engine removal is desireable see Chapter 10, Section
20.
1. Remove cylinder head as described in Section
5
2. Remove oil pan.
It
is
not necessary t o remove the front drive propeller shaft
to remove piston.
3. Remove connecting rod bolts and rod caps.
Keep bearing inserts with their respective rods and caps.
Each rod and cap assembly have identify numbers on their
side faces t o the camshaft side of cylinder block.
4. Gently tap piston and connecting rod out of cylinder top.
INSPECTION AND REPAIR
Piston Rings and Ring Grooves
1. Examine piston rings for damage, wear, and scratched or scored
conditions.
2. Use tools from Ring Expander t o remove piston rings.
3. Measure clearance between piston ring and ring groove with
a feeler gauge. I f clearance exceeds the following wear limits
replace ring.
RING-GROOVE CLEARANCE WEAR LIMIT
Top Ring
. . . . . . . . . . . . . . . . . . . . . . . . . .
0.30mm 10.012 in.)
Second
Ring
. . . . . . . . . . . . . . . . . . . . . . . .
0.25
mrn
(0.010 in.)
Oil Ring
. . . . . . . . . . . . . . . . . . . . . . . . . . .
0.25rnm (0.010in.l
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