idle screw
 

i have an nx 15 engine and having problems with the idling, found out that the idle screw was all the way in and also realised there was no spring.
someone from another forum said that you could adjust it by getting a fine screw driver and adjust it by putting the driver into where the fuel gets in to the engine, (high speed needle area)
just wanna check with here if anyone has tried that and what should i actully do, plus should i unwind the high speed screw to the top so that screw driver doesnt damaged the needle inside.

thx