Honda 2004 XR400R Owner's Manual page 169

Specifications
Engine Specifications
Valve clearance
(cold)
Spark plug
(standard)
Spark plug
(extended high
speed riding)
Spark plug gap
Idle speed
160
Technical Information
Intake: 0.004 in
(0.10 mm)
Exhaust: 0.005 in
(0.12 mm)
DPR8Z (NGK) or
X24GPR-U (DENSO)
DPR9Z (NGK) or
X27GPR-U (DENSO)
0.024 0.028 in
(0.60 0.70 mm)
1,300 100 rpm
Power Transmission
Primary reduction
Gear ratio, 1st
2nd
3rd
4th
5th
Final reduction
Standard sprocket
sizes
Final drive
2.826
2.615
1.842
1.400
1.120
0.926
3.000
drive (engine)
sprocket: 15 teeth
driven (rear wheel)
sprocket: 45 teeth
chain
D.I.D. 520V8 or
RK 520MOZ6