Hi the way that we tune engines is by starting off with the HS and LS set to flush. We then set the air gap with the reducer removed to 0.5mm. Then re-install the reducer, and fire up the engine. Once the engine is running blip the throttle and let the engine come back to idle and check the idle speed. If the idle is high, richen the LS 1-2 hours, blip throttle and let come back to idle and check again. If idle is still high, repeat until you have a smooth, steady idle. If idle is low, richen LS instead and use the same procedure.
Once you have a smooth, steady idle put the car out on the track and do a couple of laps and then start adjusting your HS to get the top end that you want. Once you have the HS set properly come back into the pits one last time and check your idle speed and adjust it using the LS to get a smooth, steady idle using the sytem above. Once you have that set your engine is tuned.