Service Bulletin SB-912-044

Hi Mike

It applies if you were supplied and run the Rotax airbox.  Most ULS engines did not.  Some kit manufacturers and LSA factory made aircraft did use them.  So the answer would be yes, if you are running a Rotax factory airbox it would apply. 

Cheers

I ordered my Rotax airbox and my 912ULS from my kit manufacturer (RANS).  They came separately.  What is confusing to me is the SB says "For all Rotax engine types 912 A/F (series)".   

Michael, good point...the type 912 A was a certified engine (not UL) and meet JAR part 22 subpart H, a day VFR motor glider engine.  The 912 F was the EASA equivalent of the FAA FAR 33 certification, it was certified to the same standards as Lycoming and others.  it was acceptable for both day and night like a Cessna or Piper for examples.  In each case the engines came standard with the Rotax airbox.  This explains why they would be mandatory for those engine models.

Cheers

I don't recall any of my colleagues having to change the carb main jets when they installed the airbox?.

One must remember that both the A and F 912 were 80 HP engines, your ULS is a 100 HP.  You have different jetting from those, they were 1211 cc engines and yours is 1352 cc.  I am guessing but assume that is the reason.  

Cheers