2006 model.-------Make sure the choke is hooked up and working properly.-------When you get the motor running and warmed up pull the choke on as a test, and report what the motor does.-----It should slow down to the point of nearly stalling.
By turning the throttle stop screw (which controls the idle speed) in (clockwise), it will open the throttle plate slightly thus increasing the idle speed allowing the engine to run while cold (and the choke is in)...similar to you "turning up the throttle a little".
That's why you may (or may not) have to adjust the idle speed when the engine is at operating speed.
This is assuming the carburetor was properly and thoroughly cleaned and there are no air leaks.
In reality, by turning the throttle stop screw in, throttle plates open slightly allowing fuel to flow from the main jet and not just the more-restricted idle (or slow speed) jet thus increasing more fuel and air into the engine
