This section examines the principles of operation, maintenance, and troubleshooting of a Power Trim and Tilt System.
Power Tilt and Trim Explained
This system is used to adjust the vertical angle of the outboard. The Power Trim adjusts the outboard´s angle for different water conditions- improving the boat´s acceleration, speed, and ride quality.
Pushing the trim button UP trims out the outboard, which raises the boat´s bow. Pushing the button DOWN trims in the outboard, which lowered the bow.
Trims Out Raises Bow
The power Tilt raises and lowers the outboard for trailering, mooring, beaching, launching and servicing. Hydraulically operated Trim and Tilt rams raise and lower the angle of the outboard.
The remote and Trim and Tilt switch control the electric motor that drives the hydraulic pump. The Power Trim and Tilt unit is located between and attached to, the stern brackets.
Hydraulic Power Trim & Tilt
We will first examine the FasTrak and Tilt unit, which has three rams, later we will look at units with single rams.
The Fast Trak hydraulic unit consists of a pump manifold assembly containing all valving,a body with two trim rams; a tilt ram; and a fluid reservoir.
Fast Trak Hydraulic Unit
The single tilt ram also serves as a shock absorber if the outboard strikes a submerged object. This safety feature is an important function of the Power Trim and Tilt System. By absorbing much of the energy upon impact, the tilt ram helps prevent the outboard from breaking off the transom or flipping over into the boat. Both Power Trim and Power Tilt are operated by pushing the Trim and Tilt switch in the desired bow direction-either bow up or bow down. Most large outboards will move until the Trim and Tilt switch is released, or the outboard reaches the limits of the Trim and Tilt range. On models that use a FasTrak unit, the trim range runs from 0 to 21 degrees. In the trim range, the short trim rams contact the swivel bracket. The tilt range runs from 22 to 75 degrees. Only the large center-tilt ram supports the outboard in the tilt range. Internal pressure release valves prevent the unit from moving the outboard into the tilt range while it is under power.
When the Trim and Tilt switch is pushed UPWARD, the electric motor drives the hydraulic pump, forcing fluid into the bottom of the trim and tilt rams.
The fluid forces the pistons outward, moving the outboard UPWARD through the trim and tilt ranges.
Trim and Tilt relays, located on the engine, control current flow from the battery to the electric motor. Older models have two individual relays, one for up and the other for down. Newer models incorporate two relays in a single module.
Old Trim and Tilt Relays
New Trim and Tilt Relay
When you push the Trim and Tilt switch DOWNWARD, the relays reverse the direction of current flow to the electric motor. This reverses the direction of fluid flow, causing the outboard to move DOWNWARD
Current Flow Switch Downward
Many outboards have a single-ram trim and tilt unit.
This unit combines the trim and tilt functions in a single ram; it has no separate trim range. Otherwise, its operation and service procedures are similar to FasTrack units.
Single Ram & Tilt Unit
Maintenence and Adjustments
To ensure proper operation of the Trim and Tilt and its built-in impact protection system, the fluid must be at the correct level. To access the fluid reservoir, tilt the outboard all the way up. Engage the tilt support lever or trailering bracket. Lower the outboard until it is resting solidly on the stern brackets.
Tilt support lever/ Trailering Bracket
Remove the filler cap and check the fluid level. If the fluid level is low, add the recommended fluid. Some models require Evinrude/Johnson Power Trim and Tilt and Power Steering Fluid.
Others use Evinrude/Johnson Biodegradable Trim and Tilt Fluid. Check the service manual or operators guide to determine the correct fluid. With the unit at full tilt, add fluid until the fluid level is even with the bottom of the fill cap hole. Replace the filler cap.
Trim and Tilt fluid
To return the outboard to its original position, tilt it all the way up. Disengage the tilt support or trailering bracket.
Lower the outboard. Purge any air in the system by cycling the unit up and down for at least five complete cycles. Check the fluid level again, and add more fluid if necessary. Some models have a tilt limit cam to limit the maximum tilt-up travel and prevent the outboard from contacting the boat´s motor well.
To REDUCE the amount of tilt UP, place the outboard in its normal operating position. Rotate the tilt limit cam by pulling the tab forward and up. Check your adjustment by tilting the outboard all the way up. Readjust the tilt limit cam if necessary. Be aware that if the gearcase hits an object at high speed, the tilt limit cam will NOT prevent the outboard from tilting fully and contacting the motor well. If this happens, it could damage the outboard and boat, and injure boat occupants.
Outboard Hitting an Object
If the full bow-down trim angle requires adjustment, move the trim limit rod, also called the thrust rod, by removing the clip on one end rod. Reposition the rod and reinstall the clip. The direction that you move the trim limit rod will determine if the full bow-down position is increased or decreased.
On two-cylinder models, move the trim limit rod out to decrease the trim-in angle. The trim gauge indicates the trim angle of the outboard. A trim sending unit, attached to the stern bracket, varies the electrical resistance to the trim gauge as the outboard moves up or down. The trim indicator needle can be adjusted by pivoting the trim sending unit located on the stern bracket.
Trim Gauge Sending Unit
If you need to adjust it, raise the outboard and engage the Tilt Support Lever or trailering bracket. Move the trim limit rod to hole number 3. Or you can simply insert a thrust rod into hole number 3. Adjust the sending unit by loosening the screws and pivoting the unit up or down. Do not remove the screws; they should remain snug against the sending unit.
Trim Limit Rod
Disengage the tilt support lever and lower the outboard against the trim limit rod.
Observe the trim gauge. If the needle does not show center position, raise the outboard. Engage the Tilt Support Lever or trailering bracket. Adjust the sending unit by pivoting it up or down, then lower the outboard against the trim limit rod to verify the adjustment.
Repeat this process until the needle is at the center position. Then tighten the two sending unit screws.
Power trim adjusts the outboard’s angle for different water conditions – improving the boat’s
acceleration, speed and ride quality.
Power tilt raises and lowers the outboard for trailering, mooring, beaching, and launching.
The power trim and tilt unit is located between, and attached to the stern brackets. It consists of:
• a pump manifold assembly containing all valving
• a cylinder body containing the hydraulic cylinder(s)
• an electric motor
• a fluid reservoir
The remote power trim and tilt switch controls the direction of the electric motor. The electric
motor drives the hydraulic pump.
Power trim and tilt units are equipped with a manual release valve to raise or lower the outboard
When replacing internal components, use only the correct parts catalog for the model you are
servicing. Some internal components might appear similar to those in other hydraulic units, but
could have different operating pressures and characteristics. Interchanging components could
have an adverse effect on the unit’s operation and safety features.
Before returning the outboard to your customer, make sure:
• The manual release valve is tightened (turn clockwise) to reactivate the outboard’s shock
absorption protection, reverse thrust capability and all the trim/tilt functions.
• The trim limiter rod is installed and in the same location as it was when the outboard was
brought in for service. Leaving the trim limiter rod out, or inserting it closer to the boat,
will allow the outboard to trim in farther than expected by your customer. Unexpected
additional trim-in could cause loss of control.
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