Carburetor Adjustment; Valve Clearance Adjustment - Yamaha XTZ 125K Owner's Manual

Carburetor adjustment

The carburetor is a vital part of the engine. Adjusting should
be left to a Yamaha dealer who has the professional
knowledge, specialized data, and equipment to do so
properly. However, the following may be serviced by the
owner as part of routine maintenance.
CAUTION:
The carburetor was set at Yamaha factory after many
tests. If the settings are changed, poor engine
performance and damage may result.

Valve clearance adjustment

The correct valve clearance changes with use, resulting in
improper fuel/air supply or engine noise. To prevent this,
valve clearance must be adjusted regularly. This adjustment,
however, should be left to a professional Yamaha service
technician.
6-12