Fuel / Exhaust
4.33
Idle Speed Adjustment
1. Connect a tachometer according to the
manufacturer’s instructions.
2. With craft in the water or test tank, start engine
and let it idle.
3. Adjust idle speed to specifications by turning the
idle speed screw in (clockwise) to increase or out
(counterclockwise) to decrease idle speed.
4. Check throttle cable free play and oil pump
adjustment and adjust if necessary.
Mixture Screw Adjustment - Base Setting - Keihin
CAUTION:
The low speed (idle) mixture screw base settings are determined at the factory using a flow meter. Limiter caps
are then installed to allow only slight adjustment of the screws in each direction to compensate for changes in
altitude and temperature. The base settings should not be changed. If large adjustments are necessary for proper
mixture, the carburetors, fuel system, and engine should be inspected to find the cause of a rich or lean condition.
(See Lean Condition T roubleshooting in Maintenance section.) If the carburetor has been tampered with or disas-
sembled before exact base settings were recorded, use the following procedure to adjust each screw. Note:The
base settings are for elevations between sea level and 3000 ft. (900 meters).
1. Remove limiter cap(s).
2. T urn mixture screw in until lightly seated, then turn
screw out the specified number of turns (see
specifications in beginning of this chapter).
3. Reinstall limiter cap(s) with tab positioned
mid-way between the stops to allow slight
adjustment in each direction.
4. Test the craft under actual operating conditions to
verify proper mixture.
Idle Speed Screw
Idle Speed (in water)
1350 ± 100 RPM
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