Yamaha MZ250 Owner's Manual
![Yamaha MZ250 manual cover](/images/023b056916f340d475759d1b/thumbs/thumb175x175.webp)
Yamaha recommends using SAE 10W-30 or 10W-40 engine oil for the MZ250, ensuring it meets the API service classification of SJ or higher.
It is advised to change the engine oil every 50 hours of operation or at least once a season to maintain optimal engine performance.
The recommended spark plug for the MZ250 is NGK BPR6ES. Ensure the spark plug gap is set between 0.7 mm and 0.8 mm.
Check the fuel level, ensure the fuel valve is open, inspect the spark plug for wear or fouling, and verify that the ignition switch is in the correct position.
Drain the fuel tank, change the oil, remove the spark plug and add a few drops of oil into the cylinder, then replace the plug. Store the engine in a dry location.
Remove the air filter cover, take out the filter, and wash it with warm soapy water. Rinse thoroughly, let it dry, and apply a light coat of air filter oil before reinstalling.
Ensure the cooling fins are clean and unobstructed, check the oil level, and verify that the engine is not overloaded or running in extremely hot conditions.
Locate the idle speed screw on the carburetor; turn it clockwise to increase idle speed or counterclockwise to decrease it, aiming for the recommended range of 1,500 to 1,700 RPM.
Black smoke indicates a rich fuel mixture. Check and clean the air filter, inspect the carburetor settings, and ensure the choke is not engaged while the engine is warm.
Yes, tighten the cylinder head bolts to a torque specification of 18 Nm (13 ft-lb) in a crisscross pattern to ensure even distribution.