Rotax 915 i A series Maintenance Manual page 221

CYLINDER HEADS (BOTH)
REPAIRED PER ENGINE SIDE
Tightening torque procedure:
NOTE
Assemble with clean parts only! Remove any re-
sidual carbon or oil from the mating surfaces of
cylinder heads and cylinders.
Step Procedure
1 Raise the cylinder and cylinder head until
the centring collar of the cylinder engages
in the cylinder head.
NOTE
A slight "click" can be heard as they
align together.
2 Clean and degrease all threads of studs.
NOTE
Collar cap M8 and collar nuts M8 also
must be clean and free from residues.
3 Lubricate the contact area for the collar
cap nuts M8 with grease.
NOTE
No grease for collar nuts M8 contact
areas!
4 Hand-tighten 2 collar cap nuts M8 and 2
collar nuts M8 evenly (maximum 5 Nm/44
in. lb), until cylinder head rests on
cylinder.
5 Attach the cylinder aligning tool part no.
877263 to the intake flange of the cylinder
heads with 4 Allen screws M6x25 and
tighten to 10 Nm (89 in. lb).
NOTE
This aligns the cylinder heads to en-
sure a flat support for the intake
manifold.
Effectivity: 915 i A Series
Edition 0/Rev. 0
BRP-Rotax
MAINTENANCE MANUAL HEAVY
Figure 8.49: Typical
Cylinder aligning tool
1
877263
Intake flange
3
Step Procedure
6 See following Fig.
Tighten the nuts in torque sequence fol-
lowing these steps:
Step 1: all collar cap nuts M8 and collar
nuts M8 with 10 Nm (89 in. lb.).
Step 2: all collar cap nuts M8 and collar
nuts M8 with 30 Nm (-5 Nm) / 265 in. lb.
(-44 in. lb).
NOTE
Perform step 3 sequentially for each
cylinder head nut one at a time follow-
ing the torque sequence in following
figure
Step 3: Loosen each collar cap nut M8 or
collar nut M8 360° then tighten to 10 Nm
(89 in. lb.) + 150°.
2 Allen screw M6x25
72–30–00
Page 35
August 01 2018