Honda CRF125F 2020 Owner's Manual page 160

Specifications
Engine Specifications
Valve clearance
(cold)
Spark plug
(standard)
Spark plug gap
Idle speed
150
Technical Information
Intake: 0.004 in
(0.10 mm)
Exhaust: 0.006 in
(0.15 mm)
CPR6EA-9 (NGK)
0.031- 0.035 in
(0.80 - 0.90 mm)
1,400 ± 100 rpm
Power Transmission
Primary reduction
Gear ratio, 1st
2nd
3rd
4th
Final reduction
Final drive
Power Transmission
Drive chain
freeplay
New chain length
Used chain service
limit length
3.250
3.181
1.705
1.238
0.916
CRF125F: 3.538
CRF125FB: 3.769
chain
1–1 3/8 in (25–35 mm)
20.0 in (508 mm)
distance between a
span of 41 pins
20.4 in (518 mm)
distance between a
span of 41 pins