Wrong, the idle adjustment screw adjusts AIR (not fuel) so the idle is no where close. At 1/2 turn out there is not enough "air" mixed into the fuel to burn clean and run smooth.
You have a gummed up idle passage. The idle should be around 1 1/2 turns to get enough air into the mix.
Should idle rock solid and smooth at 7/800 and 700 in gear at idle easily.
Dave Neptune
