Cylinder Head - Removal - Rotax MMH-912 Series Maintenance Manual

3.10) Cylinder head — removal
See Figs. 72-57 and 72-58.
If components of several cylinders are disassembled, they must be marked to
ensure correct coordination at refitting.
Remove allen screw M6x25 (1) and washer from valve cover (2) and lift off valve
cover and large and small O-ring. Remove crosswise 2 flanged nuts (3) with
washers (4) and two collar cap nuts M8. The collar cap nut is inside the valve
cover and has a sealing edge.
◆ NOTE:
■ CAUTION: Do not damage the sealing surface!
Using both hands, carefully pull the complete cylinder head off the cylinder (5).
Fig. 72-57
00277
Effectivity 912/914 Series
Edition 1 / Rev. 3
BRP-Powertrain
Maintenance Manual
Check the radial gear backlash at the propeller flange (9) with the dial
gauge (8), dimension (GB18). See 72-00-00 sec. 4.
Check the friction torque. See the relevant Manual (Line Maintenance)
12.00.00 chapter 7 of the corresponding engine type 912 Series and
914 Series.
Remove crankshaft locking screw and fit crankshaft plug screw M8 x
20 with new Cu gasket ring and tighten to 15 Nm (133 in.lb). For
verification turn crankshaft with spanner 24 a/f on hex. screw on
magneto side.
There is no washer required under the collar cap nut.
On newer engine versions, no washers (4) are fitted. They can
be left out during assembly on all engine versions.
1
5
2
3
4
72-00-00
page 55
October 01/2010