RE: ROSSI Blackmagic tuning??
Okay. one is your high speed needle. top one.. u use this to tune the engine to specss.. like for full power. dont lean. u always wont a nice stream of blue smoke coming from the exhaust if not u will burn the motor up and damage its life. thats the main one that you will adjust. the one on the sidde.. thats it on in the carb with a metal peice around is the low speed. this is adjusted for your acceleration.. helps.. but it should be good until you break the engine.. and that last one is your idle. adjust so your engine runs whille all the wheels are off the ground and dont rotate.. hope this helps. if not go to google and type in nitro engine tuning.. then youll find diagrams and instructions.. your manuel should tell you to..,