Yamaha Yz250f 2012 Workshop Manual
Posted By admin On 31.01.20
The air/fuel mixture will vary depending on atmospheric conditions. Therefore, it is necessary to take into consideration the air pressure, ambient temperature, humidity, etc., when adjusting the carburetor. Perform a test run to check for proper engine performance (e.g., throttle response) and spark plug(-s) discoloration or fouling. Use these readings to determine the best possible carburetor setting. It is recommended to keep a record of all carburetor settings and external conditions (e.g., atmospheric conditions, track/surface conditions, lap times) to make future carburetor setting easier. The air density determines the richness or leanness of the air/fuel mixture.
Yamaha Yz250f 2012 Workshop Manual Pdf
Higher temperature expands the air with its resultant reduced density. Higher humidity reduces the amount of oxygen in the air by so much of the water vapor in the same air. Lower atmospheric pressure (at a high altitude) reduces the density of the air. The FLATCR carburetor has a primary main jet. This type of main jet is perfect for racing machines since it supplies an even flow of fuel, even at full load. Use the main jet and the jet needle to set the carburetor. The FLATCR carburetor is manufactured with a pilot screw.
Yamaha Yz250f Service Manual Pdf
The pilot screw adjustment ranges from fully closed throttle to 1/4 open throttle.