Yamaha YFZ450R 2017 Owner's Manual page 43

7. Loosen the clamp screw at the throttle body
side, and then disconnect the air intake duct
from the throttle body.
1. Clamp screw
2. Air intake duct
8. Loosen the locknut.
9. Turn the spring preload adjusting nut in direc-
tion (a) to increase the spring preload and
thereby harden the suspension, and in direc-
tion (b) to decrease the spring preload and
thereby soften the suspension.
1 2
4-19
(a)
(b)
1. Locknut
2. Spring preload adjusting nut
3. Special wrench
TIP
 A special wrench can be obtained at a Yamaha
dealer to make this adjustment.
 The spring preload setting is determined by
measuring distance A, shown in the illustration.
The shorter distance A is, the higher the spring
preload; the longer distance A is, the lower the
spring preload. With each complete turn of the
adjusting nut, distance A is changed by 1.5 mm
(0.06 in).
1
2
4
3