Yamaha WR250F(N) Owner's Service Manual page 658

SETTING
EC72N000
Drive and driven sprockets setting parts
Part name
Drive sprocket 1
(STD)
Rear wheel
sprocket 2
(STD)
EC721002
Tire pressure
Tire pressure should be adjust to suit the road
surface condition of the circuit.
Standard tire pressure:
100 kPa (1.0 kg/cm
Under a rainy, muddy, sandy, or slippery
condition, the tire pressure should be lower
for a larger area of contact with the road sur-
face.
Extent of adjustment:
60 ~ 80 kPa
(0.6 ~ 0.8 kg/cm
Under a stony or hard road condition, the tire
pressure should be higher to prevent a flat
tire.
Extent of adjustment:
100 ~ 120 kPa
(1.0 ~ 1.2 kg/cm
7 - 12
T U N
Size Part number
13T 9383B-13218
48T 5GS-25448-50
50T 5GS-25450-50
52T 5GS-25452-50
54T 5PH-25454-50
2
, 15 psi)
2
, 9.0 ~ 12 psi)
2
, 15 ~ 18 psi)