I have a Rossi Pixy engine .12 and seem to have 4 needle settings on it.
The needle that is pointing to the sky is the High end setting
The other 3 not too sure
I have one that is on the end of the slide Carb, one that is opposite to that and one next to that.
I seem to of got the motor running alright its just a bit of a pain not knowing what they do.