The 2/3 to full throttle fuel adjustment on the tuner is made with the Red Mode...
-To adjust the Red Mode, push the Mode button 3 times while the motor is idling(Green>Yellow>Red), and 1 or 2 Red lights will display to show the current position. If the stock unaltered position for your tuner is light #3, then pushing (+) moving to the right of light #3 is richer(higher number). Moving to the left (-) of light #3 is leaner (lower number). Wait 10 seconds and the adjusted setting will be stored and ready to use.

Sequence to adjust Red 2 steps richer: MODE, MODE, MODE -displays a Red light, (+), (+)

Note: See the tuner instructions. The tuners will use either light #2, #3, or light #4 as the standard factory setting (unaltered signal).

-If this was a carburetor, and a #170 main jet was stock jetting (light #3 on the tuner), then moving to the right (+) is similar to using a bigger main jet, #172 (lights 3-4) or #175 main jet (light 4). Moving the Red mode setting lower (-) is analogous to using a smaller main jet #168 (lights 2-3). See Below-