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

I'm not sure how your engine could be "richening" on the initial climb out. The engine should be at WOT on climb out, so the regulator won't be having any effect, just the high speed needle valve. The HS needle sounds like it might be in too far, and so you might actually be lean on the high end, and that would be consistent with the hard starting problem as well. But if your regulator screw is out past flush, that would normally indicate a setting too rich, so I'll bet you've got some trash in the regulator, and you've had to richen the regulator some trying to compensate for it. Try cleaning it out, and while you're at it check the diaphragm and the gasket under the cover.

You might also check for an air leak on the pressure side of the regulator, the side where the check valve is located. If you're losing pressure there, it could cause you to lose your prime and force you to prime the carb with fuel before it will start. Check for pinholes, loose connections, etc. Good luck!

David