I have a 912 ULS that runs rough after the engine is warmed up and flying - turning the ignition switch it appears on both A and B systems but is more pronounced on B .
I have done the following:

- replaced the carb floats and also sent the carbs to Lockwwood, they gave them a clean bill of health
- replaced the ignition module and tried on both sides
- replaced the plugs
- replaced two double ignition coils ... one showed ohm variation with heat
- gaped the trigger coils
- installed carb heat

I'm out of ideas --- any suggestions?

Karl