Adjusting The Drive Chain Slack - Yamaha YFM70RY Service Manual

d. Tighten the locknut.
e. Slide the boots to their original positions.
L LLL L LLL L L LLL L
EAS21390

ADJUSTING THE DRIVE CHAIN SLACK

TIP
Measure the drive chain slack halfway between
the drive axle and the rear axle.
ECA13550
NOTICE
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 swing-
arm or cause an accident. Therefore, keep
the drive chain slack within the specified lim-
its.
1. Check:
• Drive chain slack "a"
Out of specification → Adjust.
Drive chain slack
25.0–35.0 mm (0.98–1.38 in)
2. Adjust:
• Drive chain slack
M MMM M MMM M M MMM M
TIP
The drive chain slack is adjusted by the rotation
of the rear axle hub.
a. Loosen the rear axle pinch bolts "1".
6
5
a
L LLL L L LLL L L LLL L
M MMM M M MMM M M MMM M
TIP
Loosen the rear axle pinch bolts in the proper se-
quence as shown.
b. Insert an appropriate shaft "2" in the hole "4"
of rear axle hub "3" so that the sprocket
bracket "5" does not move.
LLL
c. Shift the transmission into the neutral posi-
tion.
d. To loosen the drive chain, push the vehicle
forward, and to tighten the drive chain, pull
the vehicle backward.
ECA1S3L001
NOTICE
Excessive chain slack will overload the en-
gine and other vital parts; keep the slack
within the specified limits.
e. If the chain slack cannot be adjusted, replace
the sprockets and drive chain as a set.
f. Tighten the rear axle pinch bolts "1".
TIP
• Tighten the rear axle pinch bolts "1" in the prop-
er sequence as shown.
• The chain should be cleaned and lubricated af-
ter every use of the vehicle.
MMM
L LLL L LLL L
3-26
3
4
4
2
2
Rear axle pinch bolt
21 Nm (2.1 m·kg, 15 ft·lb)
1
3
1
L LLL L L LLL L L LLL L
CHASSIS
5
1
3
1 1
4
2
1
L LLL L LLL