wise) permits more fuel to enter the air stream and makes the mixture richer. Avoid using too lean a
mixture. Good performance and fuel economy depend on an idling mixture that is well balanced.
(3) Hold the throttle approximately half-open. Turn the main jet adjustment needle clockwise until the engine
begins to run irregularly, indicating a lean mixture. Then turn the needle back out slowly and carefully,
counting the complete turns of the needle required before the engine begins to show a trace of rich mixture.
The final main jet adjustment will be a point halfway between the lean point and the rich point. Hold the
needle firmly, and tighten the packing nut to prevent leakage of fuel around the needle.
Figure 23. Carburetor adjustments.
66
