Recommended 912ULS Air Filter?

Hi Michael,

Your legislative environment may require that you use factory/Rotax parts.

If legislation is not a factor, then you are at liberty to use whatever you choose AT YOUR OWN RISK.

In Australia, my home built aircraft (Sonex) is considered to be experimental and I can use whatever components I wish.

I would advise that when contemplating using non Rotax stuff, you start with knowing the Rotax specifications for that part. You can then compare the non Rotax with the factory part and if satisfied, use it with confidence.

Alternative air filters may be a problem. I have found K&N to be very evasive. Do not tell them its for an aircraft. When asking for a compatible filter, use Rotax recommended standards, dimensions, air flow, restrictions, etc (without reference to Rotax) you may be lucky & get more help than I did.😈

All my customers in all their different plane's use K&N. Cleanable and reusable plus they have good airflow.

I had a friend who's EGT's were always too high in cruise and he always had to throttle back. He had a very tight paper filter. Put a K&N in place and his EGT's dropped 125F across the board.

Thanks, Roger.  My kit manufacturer (RANS) has SN-2540 on the part list, but I don't see that one on the K&N site--perhaps discontinued?  Do you have a K&N part number?  Thanks for all your many helpful posts here!

Mike

Thanks...all good points.

Sean wrote:  

Alternative air filters may be a problem. I have found K&N to be very evasive. Do not tell them its for an aircraft. When asking for a compatible filter, use Rotax recommended standards, dimensions, air flow, restrictions, etc (without reference to Rotax) you may be lucky & get more help than I did

A bit of explanation for you.  K&N many years ago was sued in the USA for an accident.  The 2 stroke pusher aircraft using the K&N had a filter come off and hit the prop.  The metal end broke the prop and there was a crash, fatal as I recall.  K&N lost in the case.  After that point they no longer want there filters on an aircraft engine.  The Rotax filter has no metal end.  The Rotax filter has a safety wire loop as part of the filter base.  The instructions are clear in that filters must be attached using safety wire....all makes good sense but it then makes that filter a limited production run filter and it clearly is sold via the Rotax network under  Rotax part number.  Yup it costs more, welcome to aviation. 

Cheers