912UL Rough Idle Comment
I have a message that I feel is worth passing on to Rotax 912UL &ULS owners. I have a 2007 80hp 912UL and it has not idled well for hundreds of hours in the 1750-1800RPM range. I have had the carbs. rebuilt as required and balanced by several different mechanics and the rough idle has remained. I had settled in to believing this is the best it will do. Mine even has a slipper clutch on it.
Well to my amazement a mechanic from Denver who I ran into told me to check the grounds on the ignitions. I found both grounds, where they attach to the manifold extremely corroded. I cleaned them up till they shined and put them back on. Then I took the hex screw holding the rear of the ignition modules down out, as there were two wires that joined under the hex screw. They were both corroded.
Long and short of it is I cannot believe I am setting behind the same motor as it idles really nice. Who knew that such a simple repair would yield such wondrous results and the cost was $0.00.
I am sure this is no surprise to you but it may be valuable information to other Rotax owners. Please pass it on.