If it runs well and does not miss-fire, the jetting is not excessively rich.  It takes a lot of combustion heat and heat in the exhaust system to burn the two stroke oil.  The only way to keep heat in the pipe is by riding the bike hard.  If you spend the majority of your time at low RPM and partial throttle you will always have oil dripping out of the exhaust flange and muffler even when the jetting is spot on and running a 50:1 premix ratio.

The LTs were not designed to be used as putt putt putt quads.  That is what 4 strokes were designed for.   If you are running  stock carb a 280 main jet should be too lean.