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. 




10316_1_912iS Stator.jpg (You do not have access to download this file.)
  • Re: 912iS Stator Failures

    by » one month ago

    Have same problem, following.

  • Re: 912iS Stator Failures

    by » one month ago


    Fill in the customer service information report, CSIR, and state your case.  I know that you can document it correctly.  Copy the log entries also. It is very possible that they will cover this for the cost of parts, you would be on the hook for labor.  Make a request for goodwill to your Rotax iSC to update to the new oil spray system.  No point in putting it back in the way it was.  

    My own opinion is to look for the new aftermarket mosfet regulator coming out from RS Flight Systems.  I am told it is perhaps coming out next month.  



  • Re: 912iS Stator Failures

    by » one month ago


    Thanks, I will fill out the report.  I have already bought all the parts for both the repair and upgrade, but who knows, it can’t hurt.  The hardest thing was paying $400 for a new regulator that I know it will want to replace once the new type is available. But even though mine was probably OK, I  could not bring myself to do all this work and then use the old regulator.  At least I don’t have to pay labor, I have both LSRM and iRMT certs so I’m doing the work myself.  

    Thank you said by: Rotax Wizard

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