Clockwise = faster idle, and out is counter-clockwise = slower idle. Uh, if its like mine, then the rubber part that sticks up is like a cap that slips onto the actual adjust screw. and its just spins without spinning the adjust screw itself. So you have to peel up the whole rubber cover and screw the metal adjust screw itself to adjust the idle.
kinda hard to explain.
And yes up means the choke is on, down is off.
Also try changing the spark plug. Once when it went bad on mine, it would start and idle, but if i took the choke off or twisted the throttle it would shut off, i changed the plug and it worked perfectly.