ORIGINAL: MinnFlyer
This engine has an ''Air Bleed'' carb. This means that the low end is adjusted but regulating airflow as oppsed to fuel flow.
The carb should have 3 adjustments (See pic.) The Barrel Stop has nothing to do with the mixture. It holds the rotating barrel in place and also acts as a stop to prevent the barrel from rotating too much. This screw should never need adjusting.
The High Speed Needle is for adjusting the hight end. As you turn it in (Clockwise) it will reduce the flow of fuel which will ''lean'' the mixture.
The Low End adjustment is a screw that regulates airflow. This is only adjusted when the engine is at idle. When you turn it in, it reduces the flow of AIR which will ''Richen'' the mixture.
Mike, I'm not a 2 stoke guy and I never had a plane with an air bleed carb but I heard that an air bleed tunes opposite that of standard carb. Clockwise will richen the engine. I'm probably wrong. As far as fuel coming of the prop, I think his engine is so rich fuel is spitting out of the carb.