3) Cylinders Fitting - Rotax MMH-912 Series Maintenance Manual

3.16.3) Cylinders fitting

Effectivity 912/914 Series
Edition 1 / Rev. 2
BRP-Rotax
Maintenance Manual
See Fig. 72-106.
Place O-ring 87x2 on the cylinder skirt and oil the cylinder wall.
◆ NOTE: On engines with crankcases bearing serial numbers up
to S/N 27811, there is an O-ring 87x2 fitted to depress
stud bolt M8x297. This O-ring is not fitted on housing
with serial numbers above S/N 06.0010.
◆ NOTE: In case of oil leakages in the area of the cylinder barrel
a repair solution from crankcase S/N 06.0010 was
created. See SI-912-019/SI-914-021 "Oil leakages in
the area of the cylinder barrel", latest issue.
■ CAUTION : To prevent breakage to the piston rings, the appropri-
ate piston ring retainer, part no. 876978 or 876967
must be used. The gaps in the rings (2) and (3) must
be positioned in the prescribed angle range. See Fig.
72-106.
Pay attention to the position of the piston ring gaps (4). The gap in the
first piston ring (1) should be positioned in the center of the bottom
piston skirt. The ring gap in the second piston ring (2) and the gap in
the oil scraper ring (3) should be inclined away from the center of the
top piston skirt at an angle of between 25° and max. 30°. See Fig. 72-
106.
■ CAUTION : The ring gap should never be in the area of the piston
pin bore.
■ CAUTION : Check twice whether the piston pin circlips are installed
as prescribed.
Lubricate piston, compress piston rings with piston ring retainer and
carefully fit the coordinated cylinder. Proceed in the same way for the
other cylinders.
72-00-00
page 90
July 01/2008