Speed Up Mercury-Style Outboard Trim Pump

How to Speed Up the Trim of a Mercury-Style Outboard Trim Pump

Enhance the performance and speed up the trim of a Mercury-style outboard trim pump by following these steps. This guide includes adjustments to relief valves, optimizing the pump, and advanced techniques such as increasing voltage or using a speed controller. These changes should be done be experienced professionals.

1. Relief Valve Adjustment

• Locate the Relief Valves: Relief valves are found on the pump in the reservoir area under the external UP and DN ports.

• Measure and Record Settings:

  • Use a pressure gauge to measure current settings. Record the distance between the jam nut and the adjusting screw for accurate reassembly.

• Adjust Pressure for Faster Trim:

  • Loosen the jam nut on the UP relief valve (associated with raising the trim).

  • Tighten the adjusting screw clockwise to increase pressure, speeding up trim operation.

  • Each full turn of the screw increases pressure by approximately 500 psi on the UP side, it's about 350 psi on the down side.

• Retighten the jam nut to secure the adjustment.

2. Increase Voltage from 12V to 24V

• Upgrading from a 12V to a 24V motor can significantly improve speed and responsiveness by providing more power to the pump.

• Steps to Upgrade:

  • Ensure the motor is rated to handle 24V.

  • Replace or modify the power source (battery or transformer) to supply 24V.

  • Upgrade wiring and relays to handle the increased voltage and prevent overheating.

• Advantages:

  • Faster motor RPM, directly leading to quicker trim adjustments.

  • More consistent performance under heavy loads.

3. Add a Speed Controller

• Installing a DC motor speed controller allows you to fine-tune the motor’s RPM and optimize trim speed without permanently modifying the voltage.

• How to Install a Speed Controller:

  • Select a speed controller compatible with your motor and voltage range (e.g., 12-24V DC).

  • Wire the controller between the power supply and motor, following the manufacturer’s guidelines.

  • Use the controller’s dial or software (if available) to increase motor speed as needed.

• Advantages:

  • Adjustable control over trim speed.

  • Ability to balance speed and power consumption based on conditions.

4. Optimize Pump Size

• Mercury-style trim pumps often offer various pump sizes:

  • .0098, .0187, .0246, .0321 CIPR (Cubic Inches Per Revolution).

• Upgrading to a larger displacement pump increases the flow rate, allowing the trim to operate faster, provided the motor can handle the additional load.

5. Use Proper Hydraulic Fluid

• Ensure the system is filled with hydraulic fluid compatible with the pump’s specifications:

  • Prop Power Trim Fluid or mineral-based hydraulic oil with a viscosity of 32-64 cSt (150-300 SUS) at 38°C (100°F).

• Correct fluid reduces resistance and enhances speed.

6. Check for Debris or Air in the System

• Dirty and or Air in the system can reduce efficiency and slow operation.

• Clean and Bleed the System:

  • Cycle the trim up and down several times.

  • Keep the reservoir filled with hydraulic fluid during bleeding.

7. Upgrade Motor Performance

• Use high-performance motors such as:

  • DC Permanent Magnet Motors (AE/BE) or Series Wound Motors (AM/BI) for increased speed and torque.

8. Review Circuit Type

• Ensure the pump circuit (e.g., RR or RB configurations) is optimized for fast operation. Reversible circuits may require specific adjustments for speed.

• 
  

Warnings and Best Practices

• Always depressurize the system before making adjustments.

• Do not exceed the system’s maximum rated pressure (typically 207 bar or 3000 psi) to avoid damage.

• Use calibrated tools and follow all safety protocols during the process.

• Consult an experienced mechanic.

  
  

By increasing voltage, using a speed controller, and optimizing other factors, you can significantly enhance the performance of your Mercury-style outboard trim pump.

Let us know if you need further assistance. Mike Hill at 714-697-1716

Trim Pumps, Hi-Flow Outboard

Buy Now

Race Trim Pump Base + Reservoir Assembly

Buy Now

XPS Trim and Tilt Fluid

Buy Now

Flow Rate Differences for Gear Sizes

The flow rate differences for the various gear sizes (.0098, .0187, .0246, .0321) of this style hydraulic pump depend on the gear displacement, pump speed (RPM), and system characteristics.

Here are the flow rates of the gear sets:

1. .0098 in³/rev (CIPR):

   • Smaller displacement.

   • Produces the lowest flow rate, typically used for low-speed or high-precision applications.

     
     

2. .0187 in³/rev (CIPR):

   • Moderate displacement.

   • Produces higher flow than .0098 but remains efficient for medium loads.

   
   

3. .0246 in³/rev (CIPR):

   • Larger displacement.

   • Produces a significantly higher flow rate than smaller gears, suitable for faster actuation or higher volume systems.

   
   

4. .0321 in³/rev (CIPR):

   • Largest displacement available for this series.

   • Produces the highest flow rate, ideal for high-speed or large-cylinder applications.