912iS Stator Failures
I'm in the process of changing my burned out stator and I'm curious about how many others have experienced this. I have a couple of friends flying with 2019 and older 912iS aircraft which have also lost alternator B stators, and now that mine failed that's three for three. Mine has 360 hours and the other two were circa 600 hours when the stator failed. Each of these aircraft had moderate electrical loading, with dual EFIS Screens, and a standard compliment of avionics.
Rotax has had several SB's regarding this. The first was a mandatory stator replacement for some engines, but none of the three aircraft I'm speaking of were included in that SB. I believe Rotax helped with the cost of this repair since it was mandatory. The next SB introduced a new connector for the junction of regulator B to the stator leads. This was not mandatory, but I had already done this work on my aircraft. The third (SB-912-i-028) introduced a new ignition housing and sprag clutch housing that incorporates an improved oil spray nozzle for better stator cooling. The oil spray nozzle is located in the sprag clutch housing, but you have to also purchase a new ignition housing that eliminates one oiler hole from the earlier design. Again, this was not mandatory, and no financial help was offered. Newer engines are now standard with this new oil spray system.
To replace the stator, and do the oiler upgrade, the parts list comes up to about $4,100.00, and that assumes you have all the Rotax tools required to do the project, or your mechanic has them. This includes a sprag clutch housing, ignition housing, new stator assembly, new water pump shaft and seal, and other small parts required to complete the job.
I'm curious how many of you have replaced your stators, and if so, what year the engine was built. I'm not trying to build a case or anything like that, I'm just hoping the problem is solved with the new oil spray system, and newer engines are not seeing this problem.