You have a fuel delivery problem. The main power valve adjustment as per Bushog is not that critical but try opening it a bit more (CCW as seen from below).
If that doesn't help either the fuel line from the tank is restricted somehow or the carb is gummed up by today's lousy gas. Sometimes you just have to remove the carb and dip it into a good carb cleaner to solve the problem.
The idle jets or an intake leak are not part of your problem.
You may also be running too cold but I have never had this problem with my 60 and it runs pretty cold except in very hot weather.