Please explain carburetor tuning for changes in weather conditions.
Changes in air density due to changes in temperature, barometric pressure, and humidity will have a direct impact on engine performance. As the air density changes, adjustments to the fuel mixture are often necessary. Cooler, denser air can carry more oxygen per cubic foot and burn more fuel. The weather may not change enough from afternoon to evening to require mixture adjustments, but adjustments will certainly be necessary as the seasons change. Traveling to racetracks in different climates or at different altitudes may also cause a need for fuel mixture adjustments. These factors can not be overlooked when tuning for best performance.