Adjust the engine idle speed periodically on the engine at normal operating temperature.
To adjust the idle speed:

Engine oil and filter change
Throtile cable playHeadlight removal and installation
Removal
Remove the body cowling assembly. Refer to “exterior parts removal and
installation” in section 9d .
Remove the air intake pipes (1). Refer to “exterior parts removal and
installation” in section 9d .
Remove the wiring harness no. 2 (2) By
disconnecting the couplers and ...
Specifications
Service data
Drive train
unit: mm (in) except ratio
Tightening torque specifications
Note
the specified tightening torque is described in the following.
“Transmission components” “gearshift lever construction”
“gearshift shaft / gearshift cam plate componen ...
Piston ring removal and installation
Removal
Remove the piston. Refer to “engine bottom side disassembly” .
Carefully spread the ring opening with your thumbs
and then push up the opposite side of the 1st ring to
remove it.
Note
do not expand the piston ring excessively
since it is apt to be broken down. ...