Yamaha RAPTOR YFM125RA, Service Manual, Page: 86 / 300

PERIODIC MAINTENANCE
3-17
EAS2PA1305
CHECKING THE WHEEL HUB BEARINGS
Refer to “CHECKING THE FRONT WHEEL
HUBS” on page 4-7.
EAS2PA1306
CHECKING AND LUBRICATING THE SWIN-
GARM PIVOTS
Refer to “SWINGARM” on page 4-55.
EAS2PA1307
LUBRICATING THE UPPER AND LOWER
ARM PIVOTS
Refer to “FRONT ARMS AND FRONT SHOCK
ABSORBER ASSEMBLIES” on page 4-50.
EAS21390
ADJUSTING THE DRIVE CHAIN SLACK
ECA13550
A drive chain that is too tight will overload
the engine and other vital parts, and one
that is too loose can skip and damage the
swingarm or cause an accident. Therefore,
keep the drive chain slack within the speci-
fied limits.
TIP
• Measure the drive chain slack halfway
between the drive axle and the rear axle.
• When checking and adjusting the drive chain
slack, there should be no weight on the vehi-
cle and all tires must be touching the ground.
1. Check:
• Drive chain slack “a”
Out of specification
→
Adjust.
2. Adjust:
• Drive chain slack
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
TIP
The drive chain slack is adjusted by the rota-
tion of the rear axle hub.
a. Place the vehicle on a level surface.
b. Loosen the rear axle pinch bolts “1”.
c. Insert a rod of a diameter of 8 mm (0.31 in)
and length of 10 cm (4 in) “2” in the hole “3”
of rear axle hub “4”.
d. Shift the transmission into the neutral posi-
tion.
e. To loosen the drive chain, push the vehicle
forward and to tighten the drive chain, pull
the vehicle backward.
ECA4D3F005
Excessive chain slack will overload the
engine and other vital parts; keep the slack
within the specified limits.
f. If the chain slack cannot be adjusted,
replace the sprockets and drive chain as a
set.
g. Tighten the rear axle pinch bolts.
TIP
• Tighten the rear axle pinch bolts in the
proper sequence as shown.
• The chain should be cleaned and lubricated
after every use of the vehicle.
Drive chain slack
45.0–55.0 mm (1.77–2.17 in)
Rear axle pinch bolt
21 Nm (2.1 m·kgf, 15 ft·lbf)