My two year old 140 sport is not behaving like the other numerous 140's I have had. This one has always been hard to prime when starting for the first flight of the day. Other engines would be primed after just a few flips of the prop. This one has to have fuel squirted directly into the carb before it will start. It has been flying fine, but lately on initial climb out, it will richen and then abruply quit and force a dead stick. The regulator screw is a lttle further out than flush. The HS needle is about one turn out. Fuel is cool power 25% with 22% oil ( I add 4 oz of synthetic per gallon of fuel.) I know it sounds rich at the regulator, but why then is it so hard to prime? I'm about to clean the regulator. Let me know your thoughts. Thanks, Jim