Yamaha YZ125Y 2009 Owner's Manual
![Yamaha YZ125Y 2009 manual cover](/images/eaa01ce1211408eda07ff319/thumbs/thumb175x175.webp)
The recommended tire pressure for the Yamaha YZ125Y 2009 is typically 12-15 psi for the rear tire and 13-15 psi for the front tire, depending on the terrain and riding conditions.
For optimal performance, the air filter should be cleaned after every ride in dusty conditions or after every 3-4 rides in normal conditions.
It is recommended to use a high-quality 10W-40 or 10W-30 transmission oil specifically designed for two-stroke engines.
To adjust the chain, ensure there is about 1-1.5 inches of slack when the bike is on a stand. Loosen the axle nut, adjust the chain tension with the adjusters, and retighten the axle nut securely.
The correct spark plug gap for the Yamaha YZ125Y 2009 should be set to 0.7-0.8 mm (0.028-0.031 inches).
Start by checking the spark plug for fouling or wear, inspect the ignition coil, and ensure all electrical connections are secure. If the problem persists, consult a professional mechanic.
Regularly inspect the fork seals for leaks, check suspension settings, and ensure the linkage bearings are lubricated and in good condition. Consider professional service every 20-30 hours of riding.
To bleed the brakes, attach a clear hose to the brake caliper bleeder valve, pump the brake lever, open the bleeder valve to release air and fluid, close the valve, and repeat until air bubbles are gone. Ensure the brake fluid reservoir remains full.
To winterize, thoroughly clean the bike, drain the fuel system or add a fuel stabilizer, lubricate moving parts, remove the battery and store it in a cool, dry place, and cover the bike to protect it from the elements.
Improving performance can involve installing a high-performance exhaust, re-jetting the carburetor for optimal air-fuel mixture, upgrading the suspension components, and regularly maintaining the engine for peak efficiency.