Unfortunately its "usually" never that easy.
My thoughts are that by now your probably due for a complete "sync and link" on all your cables and carb adjustments.
Over time screws can loosen, control cables get old and sloppy, and throttle cams and rollers get sloppy as well. Resulting in higher or lower idle and slow speed stalling.
Or you very well could have a carb or two with a little junk in one of the jets, causing a slight lean condition, which would cause a higher idle.
Sorry if i just made it worse
The "only 100hours" is what leads me to think you may have something in the carbs from sitting.
Make sure all your linkages are lubed as well, a slight stick in a linkage will cause your problem as well