4. Maintenance
USE AND MAINTENANCE MANUAL
CHAPTER 4
MAINTENANCE
4-Strokes - Edition 00 / 2022
121
4
FWD
x2
x4
5
6
3
2
4
1
1
2
The head bolts tightening must be completed in four
steps, as described below:
1st Phase
– Tighten the head bolts to the specified torque by
performing the operation in two/three steps, following the
diagram shown in the figure.
Head bolts “1” – “4”:
30 Nm (3.0 m•kg, 22 ft•lb)
2nd Phase
– Remove bolt “1”;
– Apply molybdenum disulphide grease again to the thread
and contact surface of the bolt and washer;
– Tighten the bolt to the specified torque;
Head bolts “1”:
23 Nm (2.3 m•kg, 17 ft•lb)
– Using a marker pen, mark a reference between bolt “1” and
head “2”;
– Tighten the bolt by turning it 90° in relation to the initial
reference;
Head bolt “1”:
Specified angle = 90°
– Repeat steps 2 operations for bolts “2”, “3”, “4”;
Perform the 2nd Phase operations one bolt at a time.
Remove the bolts in the order used for tightening,
then tighten them according to the new tightening
torque.
3rd Phase
– Mark a second reference between the bolt and the head,
then tighten each bolt by a further 60° following the
tightening order of the 1st Phase;
Head bolts “1” – “4”:
Specified angle = 60°
– Tighten bolts “5” and “6” to the specified torque.
Bolts “5” – “6”:
10 Nm (1.0 m•kg, 7.4 ft•lb)
