ENGINE
Special Torque Chart
5-8
BY Service Manual
© 2009 Yanmar Marine International
SPECIAL TORQUE CHART
System Component
Model
Thread
Comments
Specification
Engine Block
Main Bearing
Replace, wash and oil
4BY2
6BY2
M10 x 80
Steel Bolts
Initial Torque
Torque Angle
23 N·m (204 in.-lb)
Plus 90°
Coolant Drain Plug to
Crankcase
4BY2
6B2Y
M14 x 1.5
Replace Sealing Ring
25 N·m (221 in.-lb)
Clamping and Guide Rails to
Crankcase
4BY2
6BY2
M14
Torque
20 N·m (177 in.-lb)
Engine Mount Nut
4BY2
6BY2
M20
Torque
300 N·m (221 ft-lb)
Torsion Damper
Torsional Vibration Damper
to Crankshaft
4BY2
M18 x 1.5
Initial Torque
1st Torque Angle
2nd Torque Angle
3rd Torque Angle
100 N·m (74 ft-lb)
60°
60°
30°
6BY2
M10 x 86
Initial Torque
1st Torque Angle
2nd Torque Angle
40 N·m (30 ft-lb)
60°
60°
Connecting Rod and
Bearing
Connecting Rod Bolts
Replace, wash and oil
4BY2
6BY2
M10 x 80
Grade 12.9
Assembly Torque
Initial Torque
Torque angle
5 N·m (44 in.-lb)
20 N·m (177 in.-lb)
70°
Cylinder Head with
Cover
Cylinder Head Bolts
Replace, wash and oil
4BY2
6BY2
M12 x 1.5
Initial Torque then
Loosen all bolts 180°
2nd Torque
1st Torque Angle
2nd Torque Angle
80 N·m (59 ft-lb)
50 N·m (37 ft-lb)
90°
90°
Seal Plug
Replace screws
4BY2
6BY2
M14 x 1.5
-
30 N·m (22 ft-lb)
Camshaft
Sprocket to Camshaft
4BY2
6BY2
M7 x 19
-
15 N·m (133 in.-lb)
Camshaft Bearing Cap Bolt
4BY2
6BY2
-
-
10 N·m (89 in.-lb)
Oil Sump
Oil Drain Plug
6BY2
M12 x 1.5
Replace Seal
25 N·m (221 in.-lb)
Oil Sump to Crankcase
6BY2
M8 x 26
-
20 N·m (177 in.-lb)
Oil Deflector to Crankcase
Lower Section
6BY2
M6 x 16
Thread-Tapping Screw
10 N·m (89 in.-lb)
Timing Case Covers
Timing Case Cover Bolt
4BY2
6BY2
-
Initial Torque of 5 N·m
(44 in.-lb)
14 N·m (124 in.-lb)
Guide Rail Pin
4BY2
6BY2
-
Apply Medium
Strength Thread Lock
and Sealer to the
Threads
20 N·m (177 in.-lb)
Plug to Timing Case Cover
4BY2
6BY2
M30 x 1
Replace Seal
70 N·m (52 ft-lb)
Plug to Timing Case Cover
4BY2
6BY2
M40 x 1.5
Replace Seal
30 N·m (22 ft-lb)