Drive Chain Slack Check - Yamaha YBR 125K Owner's Manual

Drive chain slack check

a. 20 ~ 30 mm (0.8 ~ 1.2 in)
NOTE:
Spin the wheel several times and find the tightest position
of the chain. Check and/or adjust the chain slack while it is
in this tightest position.
To check the chain slack the motorcycle must be held
straight up with both wheels on the ground and without rider.
Check the slack at the position shown in the illustration.
Normal slack is approximately 20 ~ 30 mm ( 0.8 ~ 1.2 in). If
the slack exceeds 30 mm ( 1.2 in), adjust.
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