Service manual

90-898303 2-23

Description

The V-6 outboard ignition system is alternator-driven with distributor-less

capacitor discharge. Major components of the system are the flywheel, stator

assembly, trigger assembly, 2 switch boxes, 6 ignition coils and 6 spark plugs.

The stator assembly is mounted below the flywheel and has 4 capacitor

charging coils. The 4 capacitor charging coils are composed of 2 high speed

and 2 low speed coils - 1 high speed and 1 - low speed coil for each switch

box. The low speed coils provide primary voltage for the switch boxes from

idle to approximately 2500 RPM. The high speed coils provide primary voltage

from 2000 RPM to the maximum RPM the outboard is capable of achieving.

The flywheel is fitted with permanent magnets inside the outer rim. As the

flywheel rotates, the permanent magnets pass the capacitor charging coils

producing AC voltage. The AC voltage is conducted to the switch boxes where

it is rectified and stored in a capacitor.

The trigger assembly (also mounted under the flywheel) has 3 coils. Each coil

controls the spark to 2 cylinders -1 cylinder each bank. The flywheel also has

a second set of permanent magnets located around the center hub. The

flywheel rotates, the magnets pass the trigger coils producing AC voltage. The

AC voltage is conducted to an electronic switch (SCR) in the switch box. The

switch discharges the capacitor voltage into the ignition coil at the correct time

and in firing order sequence.

Capacitor voltage is conducted to primary side of ignition coil. As this voltage

goes to ground through the primary circuit of the coil, it induces a voltage rise

in the secondary side of the ignition coil. This voltage can increase to

approximately 40000 volts before bridging the spark plug gap to ground.

The preceding sequence occurs once per engine revolution for each cylinder.

Spark timing is advanced or retarded by the movement of the trigger assembly

attached to the throttle/spark arm

Notes

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