Honda 2004 CRF150F Owner's Manual page 145

Specifications
Engine Specifications
Valve clearance
(cold)
Spark plug
(standard)
Spark plug
(cold climate;
below 5°C, 41°F)
Spark plug gap
Idle speed
136
Technical Information
Intake: 0.004 in
(0.10 mm)
Exhaust: 0.004 in
(0.10 mm)
DPR8EA-9 (NGK) or
X24EPR-U9 (DENSO)
DPR7EA-9 (NGK) or
X22EPR-U9 (DENSO)
0.031 0.035 in
(0.80 0.90 mm)
1,400 100 rpm
Power Transmission
Primary reduction
Gear ratio, 1st
2nd
3rd
4th
5th
Final reduction
Final drive
3.333
2.769
1.882
1.400
1.095
0.923
3.692
chain