Mercury 92-858058K01, Manual

Page: 51 / 150

Section 3 - On the Water
90-879172181
eng
FEBRUARY 2011 Page 43
The automatic trim tab control feature can be engaged (turned on) or disengaged (turned off). To engage the feature, press the
"AUTO" trim tab button. The trim tabs will automatically adjust as the speed of the boat is changed. Pressing it again will disengage
the feature.
With the automatic trim tab control feature engaged the port and starboard trim tab switches can be used to adjust the tabs (offset)
for natural conditions that affect the attitude of the boat. This setting of the trim tab offset continues until the automatic control
feature is disengaged and engaged again or when the key switch is cycled (turned off and on).
On vessels equipped with triples the trim tab setting on the center drive is the average of the settings on the port and starboard
drives. On quad equipped vessels the inner trim tab settings automatically set to match the outer tab position on the same side
of the vessel (port or starboard).
Manual trim tab control is available to allow trim tab adjustment when not using the automatic trim tab control feature. See
Manual
Control
.
26318
Typical automatic and manual trim tab switches
NOTE: The port or starboard manual trim tab rocker switches allow some control of the attitude of the vessel. As an example, to
achieve a port bow down attitude, you may press the port bow down rocker switch to deploy the trim tab on the starboard drive
and provide the requested vessel attitude adjustment.
Manual Control
To manually control the trim tabs for your conditions, disengage the automatic trim tab control, if engaged. Adjust the trim tabs as
needed using the individual port or starboard trim tab switches,. Manually adjusted trim tabs will stay in the position set by the
operator until the key switch is cycled off and on or the "AUTO" switch is pressed. In manual control the trim tabs do not move
during acceleration unless the operator presses the individual trim tab switches.
NOTE: In automatic trim tab control the trim tabs move to a position based on boat speed. See
Automatic Control
.
Trim Tab Offset
The trim tabs can be adjusted with an offset whether using the tabs in manual or automatic mode. Trim tab offset could be beneficial
in the following conditions:
Getting on Plane
During initial acceleration the trim tabs are automatically adjusted (automatic control) or must be
manually adjusted (manual control) to bring the boat on plane faster (bow down), to improve forward
visibility, and use less power. As the boat comes on plane in automatic control, the trim tabs are
brought up so the boat does not run with the bow too far down. For the best performance as the boat
comes on plane in manual control, the port and starboard trim tabs must be adjusted up so the boat
does not run with the bow too far down. In automatic control, the trim tabs can be adjusted (offset)
with the port and starboard trim tab switches for best performance when the boat conditions are
temporarily outside the normal operating conditions.
Smoothing the Ride
To avoid an uncomfortable, jarring ride in certain sea conditions, adjust the trim tabs using either
automatic control or manual control. As the wave throws the bow up trim tabs dampen the boat's
reaction, leveling and smoothing the ride. In a following sea, put the trim tabs up. This allows the
bow to lift, offsetting the waves which lift the stern. In milder water some boats gently porpoise. Lower
the trim tabs a little at a time until the lope disappears.
Correcting a List
A boat list (leaning to port or starboard) can be caused by unbalanced load or several sea and
weather conditions. Using the port or starboard trim tab switches, individual trim tab adjustments can
be made in automatic control or manual control to correct a list.