912 ULS 3000 RPM Vibration
in 912 / 914 Technical Questions
11 years ago
I have a Rotax 912 ULS on a Tecnam Sierra with about 600 hrs. I am getting increasing vibration at 3000 RPM, which happens to be the power setting for a 500 fpm landing decent. The vibration disappears at 3200 RPM and begins at about 2800 RPM. I have synched the carbs, and have recently rebuilt the carbs as part of the 500 hr rubber goods replacement. There was a lot of varnish on the carbs when they were rebuilt, which I removed using carb cleaner. I did not change the jets however, and just soaked them in carb cleaner. The vibration occurs no matter which mag is on. Prop has not changed so at this point I am ruling it out. I don't know if this is a carb issue or perhaps a gearbox issue. Any help would be appreciated.
