Trim Tab Control Switches - Chris-Craft 2015 21 Carina Owner's Manual

Theory of Operation: (Continued)
Increased trim may improve the ride in a head sea by allowing the bow to cleave the waves, rather than
pound over them. In a following sea, the tabs should be fully retracted for maximum steering response. A
listing condition may be corrected by applying more trim on one side. Too much trim will increase the drag
and cause the bow to "dig in" allowing wave action to veer the boat.
As the owner/operator, it is your responsibility to understand how trim tabs affect the characteristics of the
boat. The Trim Tab Owner's Manual that accompanies this vessel provides additional operating and safety
instructions, which are not repeated here.
However at a minimum:
•
Use trim tabs only at cruising speeds.
•
Do not use more tab than is actually needed for good performance.
•
Do not reduce the running angle more than -2°.
•
Do not use the trim tabs when backing or running an inlet. Damage to the cylinders and tabs will
result.
•
Fully retract the trim tabs when trailering the boat or if leaving the boat to sit in the water for any
extended length of time.
•
Spend time getting familiar with how the trim tabs affect the vessel.
Trim Tab Hydraulic System
The trim tab hydraulic system is comprised of the following components:
• Hydraulic Pump
• Reservoir
• Hydraulic Cylinders
Trim Tab Hydraulic Pump
The trim tab hydraulic pump is a 12VDC electric-driven pump. When activated, the electric motor pumps
hydraulic fluid to the hydraulic cylinder located on each tab. The high-pressure oil drives the piston down-
wards and pivots the aft section of the trim tab down below the bottom of the boat.
Trim Tab Reservoir
A hydraulic reservoir is built into the base of the pump. Fluid is drawn from the reservoir when the tabs are
driven downward and returned to the reservoir when the tabs retract. Verify fluid level in the hydraulic
pump reservoir on a regular basis. With the trim tabs completely retracted the fluid level should be about
two (2) inches from the bottom of the reservoir. To refill, remove lexan cover and filler plug located at the
front left hand corner of the reservoir. Fill with any type of Automatic Transmission Fluid (ATF) only.
Brands of ATF can be mixed.

Trim Tab Control Switches

There is a trim tab switch for each trim tab. The trim tab switches
switch control panel. When pressed, the switch activates the pressure pump that moves the trim tab in the
desired direction. To correct for a listing condition you must lower the trim tab on the listed (lower) side by
pushing the top half of the rocker switch in a half second burst until the boat is righted. If the stern of the
boat is heavily loaded use both switches to operate both tabs which lowers the bow when on plane.
3-25
Systems
(Figure 3-25) are located on the helm
3-25