Manual Control; Using Trim Tab Offset - Mercury Zeus 3000 Series User Manual

Section 3 - On the Water
Manual trim tab control is available to allow trim tab adjustment when not using the
automatic trim tab control feature. See Manual Control.
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 or adjust the offset of the trim tabs for your conditions, use the individual
port or starboard trim tab switches as needed. 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" button
is pressed. If the "AUTO" button is pressed, the automatic trim tab control feature is
engaged and the trim tabs move to a position based on boat speed. See Automatic
Control.
NOTE: When controlled manually the trim tabs do not move during acceleration unless
the operator presses the trim tab buttons.

USING TRIM TAB OFFSET

Automatic or manual control of trim tab offset could be beneficial in the following
conditions.
Getting on Plane
Smoothing the Ride
Correcting a List
Page 44
Typical automatic and manual trim tab switches
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.
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.
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.
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90-866938081 MAY 2009