Common tightening torques Rotax 912 / 914 for repairs


The following tightening torques apply to standard bolts and nuts on Rotax engines:

The part numbers and size of the copper sealing rings used can be found here:
part numbers of the copper sealing rings


Mounting locationDesignationTightening torque NmLoctiteComment
Cylinder head

Tightening sequence
See image below
M8 nut1. - Degrease all threads
2. - Grease only the contact surfaces of the cap nuts
3. - Tighten in a screwing sequence with 10 Nm
4. - Tighten in a screwing sequence with 30 Nm
5. - Loosen nuts individually by 360°
6. - finally tighten with 10 Nm + 150°
The installation and tightening of a single cylinder head or a single cylinder head nut is not permitted.
The entire procedure for tightening the cylinder heads must be carried out in the torque sequence.
New tightening instructions for all engines.

** Replaces all previous tightening instructions !

See:
SI-912-025
SI-914-026
SI-912 i-010„| |cylinder head|nut M8|22| |up to housing S/N: 27811| |cylinder head|nut M8|10 Nm + 120°| |from housing S/N: 06.0010| |cylinder head|spark plugs|20 (NGK / ND)
16 (BRP)|insert with silicone
thermal paste|see:
SI-912-027
SI-912 i-013
SI-914-028| |motor housing|CONNECTING SCREW M16X1.5|35|243| | |motor housing|banjo bolt M16 X 1.5|30| |oil pressure line| |Motor housing|screw connection 3/4-16 UNF/ M16 X 1.5|25|243|oil pressure line| |motor housing|MAGNETIC SCREW M12X1.5|25| |no sealing ring! |motor housing|locking screw blocking pin
CYL.SCREW M8X20|15| |with copper sealing ring| |freewheel housing|SK-NUT M34X1.5 HEIGHT 8|150|603| | |drive wheel|SK-NUT M30X1.5 HOEHE 12|200|648| | |Intake manifold|SK-BOLT M8X30|15|243| | |Exhaust stud bolt|SK SCREW M8X23/20|6|648| |Water pump|WHEEL|15|243| | |Solenoid wheel|SK SCREW M16X1.5×40|originally 150 Nm
45 Nm + 180°|Fit the cone of the solenoid hub with Loctite 603 !| |Ignition cover|SK SCREW M6X16|5|243| | |Ignition coil holder front|CYL.SCREW M8X16|25|243|with bracket| |Fuel pump cap|SK SCREW M8|15|243|914 / 912 iS| |Oil pump screw plug M12X1|25|Oil pressure control valve| |oil pump|HOSE NIP 13.2/9.5|15|243| | |oil pump|screw gland|25|648| | |oil pump|oil pressure sensor|15|243|cellar sensor| |oil pump|banjo bolt M10 x 1 x 19 / 30|12| |pressure oil lines (also on regulator flange)| |oil pump|CONNECTING SCREW M10X1|10|243|connection for pressure oil line| |oil pump|oil filter nipple|60|screw on oil filter| |oil reservoir|drain plug
SK-SCREW M12X12|25| |with sealing ring P/N 250010| |oil reservoir|pipe bend / hose connection
union nut|25| |hold against with open-end wrench on\\oil reservoir cover| |oil reservoir|banjo bolt M10X1X19|17| |oil return 914 from\\oil pump| |oil pump/cylinder head|TEMPERATURE SENSOR|10|243| | |propeller shaft bearing|SK-SCREW M7X16|15|243|in the gearbox housing | |fuel lines|banjo bolt M8X1|10| |on carburetor| |fuel lines|banjo bolt M10X1|15| |914| |Airbox|TEMPERATURE SENSOR|15|243| | |fuel pump|SK-NUT M8|15|243| | |float chamber cover|CONNECTION SCREW|5.5| |only 914| |Fuel line on the carburetor|SREWED-IN SCREW|10|243| | |turbo oil line|valve housing|25| | | |turbo oil line|banjo bolt M8X1X17|10| |marked with „OIL“| |oil sump tank
**only 914
locking screw with strainer20 also 915 and 916
carbon brush holder starter motorCOMBINUT M64
Magnetic hubPrerotator drive140648AutoGyro

Fit the cylinder head and bumpers. To do this, lift the cylinder into the centering of the head,
Grease the contact surface of the flanged cap nuts.
Screw on the collar nuts and collar cap nuts.
Tighten the collar nuts evenly and lightly (do not exceed 10 Nm!) until the cylinder head rests on the cylinder.
Align the cylinder heads with the fixture provided and tighten the nuts to 10 Nm according to the screw sequence and then to 30 Nm according to the screw sequence.
Loosen each screw point individually by 360°, retighten with 10 Nm and a rotation angle of 150°.