Mandatory ALERT Service Bulletin: Inspection and Replacement of Oil Spray Nozzle for ROTAX® Engine Types 912 i, 915 i, and 916 i (Series) SB-912 i-016 / SB-915 i-016 SB-916 i-006

Harry,

Unfortunately, the first and only sign of a problem would be a failed stator. The oil spray nozzle helps take heat off the stator and if the nozzle is clogged with Loctite the stator can overheat and burn out a coil. Different aircraft electrical load profiles can create more or less heat in the stator, so I don't know if 200 hours without a failure truly indicates that the oil spray nozzle is working fine. The earlier 912iS engines (like my 2016) did not have the oil spray nozzle, instead they just had an oil hole where the new spray nozzle is now attached. My stator lasted about 300 hours and when it failed, I upgraded to the new nozzle at the same time. The way I read it, you are not obligated to do the inspection since you have over 200 trouble free hours. However, if your engine is mounted such that the test tool can be inserted easily, then I would go ahead and do the test.  That way if there is a problem you can fix it before the stator fails, and you will get help from Rotax. This has been a nagging problem on the iS engines and I hope this test is a step towards finding the root cause. 

For those that seem to be in the clear based on time but are still a little concerned, could there be anything to glean about the stator condition by performing the resistance test in the SB? Do we know if there is a gradual degradation of the stator as it approaches failure?

How precise is Rotax with these serial numbers? Mine is only 53 below/before the start of the range, so I should be fine. But that seems awfully close.

Has anyone put together an Amazon (or other source) shopping list for the Regulator, Shutoff Valve, Pressure Gauge, and Flow Meter they would like to share?  My thinking is that if I could find a low pressure (0-20 or lower) regulator with built in gauge, I could save on space and have more manuevering room to insert the tool.  So far, I am only finding high pressure (>125psi) all-in-one units.   Any thoughts?

Harry

Sorry, I'm not exactly answer your question directly...but I have thought that it may not necessarily need to be assembled as shown in the diagram. Would an elbow between the special tool and meter, maybe a small length of tube, throw the flow off so much as to invalidate the test? This would reduce the necessary space for the whole setup.

We're looking for a flow greater than 4(1.05), so an acceptable reading even with some theoretical loss of flow from an elbow and some tube would be an acceptable result, right? 

If it fails but is right on the bubble, you would take whatever steps to re-test in the straight configuration?