Rotax 912 Oil Change Interval?

10 posts in this topic

Posted

For you Rotax 912 experts, what do you use for your oil change interval?  I was surprised I could not find it in the Rotax operation manual.

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Posted (edited)

40 hours if running unleaded and 25 if running 100LL and Decalin. iI think it may be in the owners manual.

fat fingers it should be 50 hours for unleaded.

Edited by wypaul

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Posted

100 hours interval if runing MOGAS fuel (unleaded) - oil and filter change.

200 hours interval  - oil, filter and spark plugs change

5 years interval - rubber parts and hoses change, fuel pump change

 

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Posted

Randy the info is in the maintenance manual  05-20-00 clearly states 50 hrs. For unleaded.  For 100LL it is not quite so clear but refer to SI-912-016.  I stand by the 25 hour figure for 100LL because that is the lower figure stated.  It would be nice if Rotax would clear this up.  I would give Hal a call and see what he recommends for his Zipper Kit engines.  If I recall correctly he also recommends 50 hrs.

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Posted

I've been doing 50 hours. I did a shorter interval for the big Oshkosh trip last year on 100LL. I changed the oil when I got back instead of waiting for 50 hours.

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Posted

Just for information, Maintenance Manual Rotax 912, just for sure I asked certified service for clarification:

Unleaded fuel (MOGAS) 100 hours

Leaded fuel (more then 30% of operations) 50 hours

Maybe it is not really clear from manual, but they told me as I wrote above

Rotax Oil chage.png

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Posted (edited)

You are correct Jenki that is what the manual appears to state.

All that said if you refer to SI-912-016 Rotax states 50 hrs when using 100LL and then states 25hrs when using Primary 100LL.

In addition they state the when not operating in ideal conditions service time should be shortened.

I will continue to make my changes in accordance with this advice because my engine is not operated in a perfect condition and use 50 hrs and 25 if I run 100LL. 

Edited by wypaul

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Posted

To be precise, there are no exact numbers in SI-912-016 regarding hours or deadlines. So far 25 hours interval I have never heard  - but could be possible in some cases. To be sure that I am keeping exact information, please find following text from SI-912-016 below:

3) Lubricant

3.1) General

Foreign particles formed during combustion are suspended in the motor oil. Together with oil components 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 corrosion 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 indicator 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 buildup (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 insufficient 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 accordance with the relevant Operators Manual.

- Pay special attention to engine operation tips (see section 6).

3.2) Operation with unleaded and low-lead fuel (less than 0.1 g/liter lead content)

Motor oils tested and released from BRP-Rotax (for use with unleaded fuel or MOGAS), which we recommend for use with our ROTAX® engine types 912 i, 915 i, 912 and 914 Series:

Brand               Description                                                    Specification      Viscosity

SHELL®               AeroShell Oil Sport Plus 4 1) 2) 3)            RON 424*         SAE 10 W-40

1) according to RON 424

2) with new formulation

3) in red bottle

* Specification RON 424: The ROTAX® Norm 424 (RON 424) is a BRP-Rotax internal standard, which is only available on special request via the ROTAX® Authorized Distributor and will not be disclosed to third parties without prior consent.

NOTE: The previous formulation of AeroShell Oil Sport Plus 4 can still be used until its expiration date.

NOTE: The coefficient of viscosity indicates the tendency of oil to flow but it is not necessarily a quality code. Country specific deviations of the viscosity are possible.

3.3) Operation with leaded AVGAS fuels

Perform maintenance checks according to the latest Maintenance Manual.

More frequent oil changes will assure timely removal of residues and oil sludge thus avoiding increased wear or operating troubles.

Motor oils tested and released by BRP-Rotax (for use with leaded AVGAS), which we recommend for use with our ROTAX® engine types 912 i, 915 i, 912 and 914 Series:

Brand              Description                                                       Specification   Viscosity

SHELL®               AeroShell Oil Sport Plus 4 1) 2) 3)             RON 424*        SAE 10 W-40

1) according to RON 424

2) with new formulation

3) in red bottle

* Specification RON 424: The ROTAX® Norm 424 (RON 424) is a BRP-Rotax internal standard, which is only available on special request via the ROTAX® Authorized Distributor and will not be disclosed to third parties without prior consent.

NOTE: The previous formulation of AeroShell Oil Sport Plus 4 can still be used until its expiration date.

NOTE: The coefficient of viscosity indicates the tendency of oil to flow but it is not necessarily a quality code. Country specific deviations of the viscosity are possible.

.

6) General engine operation requirements and operating tips

1. Keep the motor oil temperature below 120 °C (250 °F) over most of the operating period.

2. Always insure that the oil type used is adequate for climatic conditions and peak engine operating temperatures. If operational oil temperatures exceed 120 °C (250 °F), use of a mineral or petroleum based oil is not recommended.

3. For turbocharged engines ensure an adequate running cool-down period to prevent deposits by coking of oil.

4. When operating with unleaded fuels or MOGAS and when engine oil temperatures often exceed 120 °C (250 °F) use of a high quality full synthetic oil is recommended.

5. To avoid formation of condensation water in the motor oil, the oil temperature must rise at least once every operational day to at least 100 °C (212 °F).

6. Avoid extended use of carburetor air pre-heating when safe and reasonable.

7. Depending on the type of fuel used, operating conditions, and the demands of the engine mission profile it may be necessary to increase the frequency of oil changes to avoid the excessive build up of lead and other residues in the engine oil. Always adjust the engine oil change intervals to avoid excessive build up of sludge in the engine oil.

Excessive engine vibration, particularly at low idle speeds, can impair the carburetor fuel metering system leading to a too rich mixture condition. This rich mixture condition can further lead to rough engine operation and excessive carbon and lead deposits.

NOTICE

Do not use oil additives and observe the operating limits as per the relevant Operators Manual.

I hope this will help to avoid any misunderstandings.;)

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Posted

Refer to SI-016-R5 section 3.3 

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Posted

Thanks Paul and Jenki for the help.  I used 50 hrs for my Subie running unleaded so will stick to the same and shorten if I have to run 100LL at times.

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