The rotax 912 that I have has basically sat since 2003 with 17 hours on it. It appears that when it was taken off the airframe, the carbs where cleaned because when I pulled the bowls, everything looks like brand new. Now that I have it put back together the engine runs very good. However, I am still thinking about doing a carb rebuild just because of the amount of time that has gone by. Any opinions on this? If a rebuild is recommended, does anyone have any suggestions on where to get reasonably priced rebuild kits? I almost hate to mess with the carbs since it runs so good.