I just replaced both my carb flange assemblies on my 912ULS. 

I started to notice it was starting slower than usual and the idle was off from its normal smooth self but acceptable.  My run ups were good and in the air performance was good.

What prompted me to look further into the symptoms was my last landing the engine died as I was turning for a back taxi to exit the runway. My first thought was my idle was to slow but the engine had never quit on me. 

I took my cowling off and adjusted the idle, but it just didn't seem right. I then wiggled both carbs and found the problem. My right carb flange was cracked about half way around and the left carb flange was starting to crack. 

I have had the engine for 4.5 years and the engine has been running for 3.5 years since my first flight.  I had 330 hours on the engine and plane. With both flanges replaced the engine is performing like it should.

Jim

CH 701