Honda CRF250F 2020 Owner's Manual page 153

Specifications
Engine Specifications
Valve clearance
(cold)
Spark plug
(standard)
Spark plug gap
Idle speed
146
Technical Information
Intake: 0.004 in
(0.10 mm)
Exhaust: 0.006 in
(0.15 mm)
LMAR7H-9DS
0.03–0.04 in
(0.8–0.9 mm)
1,400±100 rpm
Power Transmission
Primary reduction
Gear ratio, 1st
2nd
3rd
4th
5th
Final reduction
Final drive
2.863
2.846
1.900
1.400
1.083
0.896
3.846
chain