Service manual

90-898303 2-27

TEST FOR PROPER FUNCTION OF IDLE STABILIZER SHIFT

SYSTEM

Connect timing light to number one spark plug lead (top, starboard bank).

Start the engine and allow it to idle at specified engine RPM. Place outboard

in gear while monitoring ignition timing. Timing will advance three degrees if

system is functioning correctly.

TROUBLESHOOTING IDLE STABILIZER SHIFT SYSTEM

When outboard is idling IN NEUTRAL, shift switch circuit is in the OPEN

position and system is INACTIVE.

When outboard is shifted INTO GEAR, shift switch circuit CLOSES. BIAS

VOLTAGE from each switch box is changed by a 6.8K (±.34K) resistor located

in the WHITE/BLACK lead between the switch boxes and the shift switch. The

shift switch is now CLOSED and completes the circuit to ground. THREE

DEGREES of timing advance occurs when the shift system works properly.

If the resistor is OPEN or the shift switch circuit stays OPEN, the THREE

DEGREES of advance will not occur when the outboard is shifted into gear

AND maximum timing at W.O.T. will be RETARDED THREE DEGREES.

If the resistor should SHORT TO GROUND, engine timing will be overly

advanced and damaging powerhead detonation will occur.

Connect a timing light to No. 1 spark plug lead (top, starboard bank). Start the

engine, and allow it to idle above 600 RPM, then retard the ignition timing by

slowly pulling forward on the spark advance lever. Observe that the system is

functioning by noting a rapid spark advance (as much as 9° from the idle

setting) as the engine slows down to below approximately 550 RPM.

The idle stabilizer is not repairable. Should the idle stabilizer fail to function as

described, it will require replacement.

Notes

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