Yamaha FZ09E Service Manual page 214

Refer to "ADJUSTING THE DRIVE CHAIN
SLACK" on page 3-16.
Drive chain slack
5.0-15.0 mm (0.20-0.59 In)
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.
4-74
CHAIN DRIVE