Rotax 912 uls shakes violently

I had this happen once, it was a broken /leaking carburetor rubber flange which connected the carburetor to the intake manifold.

Hello

Sorry I wrote wrong on mag drop should be 150rpm. Rubber motor insulators are new approx. 100h. Engine hours 1700h. Will disassemble the gearbox for inspection. Thanks for all the tips from a snowy Northern Sweden.

Check the carbs before you tear into the gearbox. I’ve heard this gearbox issue brought up often as an immediate go to and people fail to check the east things first before opening up the engine. 

make sure that the carbs arnt spitting fuel from the vent lines. Verify fuel height in the bowl- a crashed float will cause excess vibration from an overly rich condition and is a 2 minute fix. Many things can be done BEFORE you open up that gearbox and possibly introduce further errors. 

Also check the metal engine mounting. I just remembered I had one like this years ago and it was a broken weld on the frame.

Hi all, I'll be back when I find the error

Best

Leif Westin