Yamaha YZ125Z 2010 Owner's Manual

The recommended oil ratio for the Yamaha YZ125Z 2010 is 32:1. This means mixing 32 parts of gasoline with 1 part of 2-stroke engine oil.
You should clean the air filter after every 2-3 rides, or more frequently if you are riding in dusty conditions.
The recommended spark plug for the Yamaha YZ125Z 2010 is an NGK BR9EG.
To adjust the chain tension, ensure there is about 1.2 inches (30 mm) of slack at the tightest point of the chain when measured from the swingarm. Loosen the axle nut and adjust the chain adjusters equally on both sides.
The recommended tire pressure for the Yamaha YZ125Z 2010 is 12 psi for both front and rear tires.
Check the fuel level, inspect the spark plug for fouling, ensure the kill switch is in the 'run' position, and verify that the fuel petcock is turned on.
After each ride, clean the bike thoroughly, check for any loose bolts, inspect the chain and sprockets, and lubricate the chain. Also, check the air filter and clean it if necessary.
It is recommended to replace the fork oil every 20-30 hours of riding, or at least once a year.
Ensure the radiator is filled with coolant, check for any obstructions in the radiator fins, and make sure the engine is not running too lean. Consider checking the coolant system for leaks.
To adjust the carburetor, start with the air screw and needle clip in the stock position, then fine-tune the air screw for smooth idle and throttle response. You may need to adjust the main jet and needle position based on altitude and temperature.