Assembling The Power Unit - Yamaha 55DEHD Service Manual

Assembling the power unit

1. Install the pistons into the cylinders with
the "UP" mark on the piston crown facing
towards the flywheel magnet.
1
NOTE:
9 Apply engine oil to the pistons and piston
rings before installation.
9 Be sure to install the piston and connecting
rod assemblies into the corresponding
cylinders according to the marks a made
during disassembly.
Piston slider 1:
90890-06530
2. Set the crankshaft in the cylinder block.
3
3
3
2
NOTE:
Fit dowels 2 on the cylinder block into the
dowel holes 3 in the main bearings.
6885J11
3. Install the connecting rod bearings and
a
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NOTE:
9 Align the identification numbers b, which
you made during disassembly, on the con-
necting rod caps and connecting rods.
9 Apply engine oil to the connecting rod bear-
ings, connecting rod caps, and connecting
rod bolts before installation.
9 Tighten the connecting rod caps one by one
and slowly turn the crankshaft, then check
the crankshaft for smooth operation.
2
68850600
connecting rod caps onto the connecting
rods, and then tighten the connecting rod
bolts 4 to the specified torques in 5
stages.
b
Connecting rod bolt 4:
1st: 12 N·m (1.2 kgf·m, 8.9 ft·lb)
2nd: 35 N·m (3.5 kgf·m, 25.8 ft·lb)
3rd: Loosen completely
4th: 12 N·m (1.2 kgf·m, 8.9 ft·lb)
5th: 35 N·m (3.5 kgf·m, 25.8 ft·lb)
Crankcase
1
2
4
3
4
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5
6
7
8
9
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