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 playSpecial tools and equipment
Recommended service material
Note
required service material is also described in the following.
“Front fork components”
Special tool
...
Front brake master cylinder / brake lever disassembly and assembly
Refer to “front brake master cylinder assembly removal and installation” .
Disassembly
Remove the reservoir cap (1), plate (2), diaphragm
(3) and reservoir tank (4).
Remove the brake light switch (5) and brake lever
(6).
Remove the dust boot (7) and push rod (8).
  ...
Clutch parts inspection
Refer to “clutch removal” and “clutch installation” .
Clutch drive and driven plate
Note
wipe off the engine oil from the drive and
driven plates with a clean rag.
Measure the thickness of drive plates with a vernier
calipers. If the drive plate thickness is found to have ...