Noticeable vibration at 200+ hours 912iS Sport

Paul and others....

  I now have 620 hr on my IS and the gearbox is starting to growl too much. My question is how many hours do people have on the "oil spray" gearbox ? does it definitely cure the problem ?

Thanks Glenn

Update report. I now have 350 hours and the new oil stray updated gearbox. Running great. Typically this is about the time when I had to replace the old gearbox. So far so good.

We are on our 9th Gearbox rebuild (done a lot of hours). 

Basically a 912iS Gearbox lasts approximately 300 hrs before

the vibration and/or Starting gets worse. 

Rotax have a major problem with this engine / gearbox but are

so damn arrogant they won’t admit. We have gone backwards 

slightly and are using a Lycoming, at least its been designed by

proper engineers. Saying all these negative things its only the 

912iS Injected Engines that are the problem, the Carb. Engines

are more or less bullet proof. It will be interesting to see how the

915iS fairs. They have altered the Gearbox design but it still sounds

like a bag of spanners when you idle too slow - not a good design.

Wouldn’t touch one at the moment……

First, what is your idea of a low idle?  Anything below 1400 is going to kill the gearbox and everyone will tell you 1600 to 1800 is much better.  

Second, have you got the version with the oil sprayer inside?  This was introduced in mid 2018 I believe and solves almost all the wear issues.  It can't help you if you idle too low. 

The type 915 has a different gearbox without the dog and ram system.  The torsional damping is done with a torsion shaft that is working with friction dampers internally.  You can see this in the heavy manual if you are so inclined.  On start and shut down all gearbox engines will give you noise, that is the nature of the gearbox damping on a piston engine.  

Cheers