Joe, the engine in my first 12 ran flawlessly out of the box. It ran so well, I did not touch the carbs for 10 or 15 hours. My current mount ripped and snorted, had to be purged 3 times and took hours to calm it down. It now runs smoother than the first one, so be prepared for anything. The 912 is a great engine. I think you are going to like it.