Online Community of Zenith Builders and Flyers
I recently noticed a damp patch on top of my Rotax 912uls engine while doing a preflight check. I couldn’t see any obvious source of the leak. After doing a ground run it took a few minutes for oil to begin weeping out of the crankcase join at the top of the engine.
I thought about sealing it with JB weld but knew I would never be happy with that solution. So, I removed the engine and took it to a Rotax repair centre. When the crankcase was split there was evidence of fretting between the two halves.
The end result is a new crankcase and a much diminished bank account.
The engine was manufactured in Spring of 2002 and has 580 hours. It has been well looked after and well maintained since new and was running fine.
Photos attached below.
Two questions, please.
Were you given an explanation by the Rotax repair center for why the fretting occurred? What is the root cause?
Was a new crankcase the only solution, meaning had you kept going with a temporary fix of JB Weld, did you risk engine failure in flight?
Sorry to hear of your trouble. Airplanes have a tendency to go after your $$ reserves. Ask me how I know...or maybe don't remind me.
This is a well known problem for older engines. Some reports by owners indicate that Rotax may help with the cost of parts. You have to file an official Customer Service Information Report.
Here is a write up on causes.
Thanks for the reply Michael,
Yeah, my engine is one of the early’ish models and this is a known problem with that vintage of engine. There’s also an SB to check the crankcase for cracks. From about 2006 onwards the crankcase was improved to eliminate (hopefully) both of these problems.
With regard to the JB weld plan: I only fly about 50 hours a year so it might have kept me going for a year or maybe even two.
I would never have felt very happy with that solution though, especially if I had a passenger on board.
The fretting was never going to get better, only worse, and if I ended up in a muddy field upside down the cost would be higher.
I’ll fill out one if those Rotax CSIRs just to see what happens.
Thanks again and safe flying,
I found an honest Rotax Mechanic in Glendale Arizona. His name is Steve Beatty. Aircraft Screw performance. I had a bad experience with Rotech of Canada. Michael Moore likes them , I think there crooks.
What I was interested in was the actual cause and facts behind the problem. I provided a link and a quote from the Rotax owner's forum. It should have been totally obvious that nothing there infers my opinion one way or another.
Please avoid reacting and going after someone personally when there is no basis.
And if I may say so, bashing a company while providing no facts is poor form and informs no one. Just because this is the internet and that is so easy to do does make it fair practice.
I bought an engine from Rotech. They have been superb in every way. Five stars (out of five) for Rotech.