Copy paste from the FZ6 Forum..
Directly From the R6 OEM MANUAL for assembling the bikes
Before changing the settings, check the engine for its characteristics in normal
It is recommended that the settings be checked with an A/F measuring instrument.
Guidelines for setting
• Code C1: At 25% or less of throttle opening and at 3000 rpm or less of engine
This affects the idling stability and the feeling experienced during
Too rich an air-fuel mixture may foul the spark plugs.
• Code C2: At 25% or less of throttle opening and at 3000 rpm or more
speed:
This affects the feeling experienced during engine braking and
throttle opening.
Make a change of 2 to 5% at a time while checking for any
changes.
• Code C3: At 25% to 90% of throttle opening:
This affects the feeling experienced at half throttle opening.
Make a change of 2 to 5% at a time and check for any resulting changes.
• Code C4: At 90% or more of throttle opening:
This affects the feeling experienced at full throttle.
Adjustment to too lean a mixture will lead to engine breakdown.
Adjustment by checking the A/F is recommended.
In particular, to adjust on the leaner side, make a change of 1
time while checking for the result. 12 to 13 is a targeted A/F.
Page 29 of the Book . It's for 03' R6 which is our bike's motor
http://www.cappojim.com/uploads/how_to/fuel_map/04R6GB.pdf
And also here:
How-to: Richen or lean mixture without a power commander! : Yamaha R6 Forum: R6MessageNet : YZF-R6 Forums