Rotax has just published a new safety bulletin – SB-912-065 & SB-912-065UL – about their carburettors. At least all 912ULS (100hp) engines from serial number 6 780 228 may be affected. And perhaps some others if you changed the carburettors or carburettor floats in the last couple of years.
You can find the details at Rotax-Owner.com – Service Bulletins. You’ll need to subscribe with your email and engine number if you aren’t already a member.
Please check the bulletin as it can affect the running of your engine!