Start out with the high-speed needle at 2-1/2 to 3 turns out from closed. Set the air-bleed screw so that it's 1/2-way across the hole. Both of these are starting point. Once the engine's started, advance it to full throttle to get the high-speed needle adjusted, and then work with the air-bleed screw to set the idle. Don't try to idle too slowly, many people make the mistake of thinking that the engine will idle as slowly as larger engines. Anywhere between 2,500-3,000 RPM is considered good for this size engine.