Y SLOW 

G90 ;abs

G1 Y110 F200 
G1 Y105 F200 dial at 24.9

G1 Y100 F200
G1 Y105 F200 dial at 26.0

dial says backlash at slow is 1

Y FAST

G1 Y110 F2000 
G1 Y105 F2000 dial at 26

G1 Y100 F2000
G1 Y105 F2000 dial at 25.8 (DAYUM)

dial says backlash at fast is 0.2 => 0.005mm

Set backlash to M99 Y0.01

Y FAST Verify

G1 Y110 F2000 
G1 Y105 F2000 dial at 26.1

G1 Y100 F2000
G1 Y105 F2000 dial at 26.1