d06322.fm
SI-912 i-001R4
SI-912-016R9 / SI-914-019R9
SERVICE INSTRUCTION
27 March 2017 12-10-00
page 3 of 11
Copyright - BRP-Rotax GmbH & CO KG. All rights reserved.
3) Lubricant
3.1) General
Foreign particles formed during combustion are suspended in the motor oil. Together with oil com-
ponents that are not sufficiently resistant to heat, these foreign particles can cause parts such as
pistons, piston rings, exhaust valves, etc., to seize and lead to problems.
On turbocharged engines, failing to ensure an adequate cool-down period prior to shut-off may
lead to particle deposits and cause damage to bearings and seals. Hard oil residues can obstruct
parts of the oil system and lead to damage.
- In addition to insufficient cool-down periods, the use of unsuitable oils and not obeying oil
change intervals can especially cause such damage.
- Long-term operation with an engine that is too cold and/or operating too long with an overly rich
fuel mixture can cause water and fuel contamination in the oil, reducing its lubrication capacity.
- Furthermore, long down times with oil that contains water and contaminants can cause corro-
sion damage, especially on the bearings, with serious consequential damage.
The criteria for correct motor oil selection are:
- Correct oil viscosity for cold starts and sufficient oil pressure at high temperatures.
- Good gear wear protection.
- Avoidance of clutch slipping due to use of additives.
- Insufficient oil flow capability causes too much volume to remain in the engine, leading to low
oil level in the external oil tank. This can only be detected during testing with an oil level indica-
tor installed on the oil tank.
- Ability to withstand combustion products containing lead, which enter the oil during AVGAS
operation.
- High oil temperature durability. This is especially important for the turbo engine due to the risk
of oil carbon buildup on the bearing and sealing seats of the turbocharger. The oil carbon build-
up (coking) can also flake off and block/restrict the oil return passage
Conclusions
- If possible, operate the listed engine types using unleaded or low-lead fuel. (AVGAS 100 LL is
not considered low leaded in this context.)
- Use the recommended motor oils tested and released by BRP-Rotax according to section 3.2
of this SI.
- Use only oil which is classified by ROTAX
®
standard (RON)!
- Due to high stresses in the reduction gears, oils with gear additives such as AeroShell Oil Sport
Plus 4 are highly recommended.
- Because of the incorporated friction clutch, oils with friction modifier additives are unsuitable
because this could result in clutch slipping during standard operation.
- Avoid oils strictly specified for use in Diesel engines. These may not be suitable due to insuffi-
cient high temperature properties and additives that may affect the operation of the slipper
clutch in the gear box.
- On turbocharged engines, always conduct a cool-down run before shutting down in accor-
dance with the relevant Operators Manual.
- Pay special attention to engine operation tips (see section 6).
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