Electronic Power Steering (EPS) Installation Guide in PDF

Mike Hill
Oct 28, 2024
4 min read

Updated: May 12

*For 220W, 400W, and 600W EPS Models – Designed for US F1, F1H2O & Race Boats with Cable and Pulley Steering Systems*

Installing an Electronic Power Steering (EPS) system can transform the handling of your high-performance race boat by delivering responsive, effortless steering control under high G-loads, rough water, and aggressive cornering.

Whether you're racing in US F1, F1H2O, or any high-speed competition class using a traditional cable and pulley steering system, this guide will walk you through the professional installation of your EPS kit and help you choose the right model for your setup.

Choosing the Right EPS System for Your Boat

The EPS system comes in three powerful configurations to match the specific demands of various racing engine classes. Each model is designed to enhance boat control, reduce driver fatigue, and improve overall performance under race conditions.

The 220-Watt (220W) EPS system is best suited for lightweight, lower-horsepower race boats equipped with engines up to 125 HP. This includes popular models such as the OMC SST-45, SST-60, and Yamaha 3-cylinder outboards. This system delivers reliable electronic assist during sharp turns, rough water runs, and "on-the-pad" balance where fine adjustments are critical. If you’re running a smaller, nimble hull in competitive classes, the 220W is a perfect match.

The 400-Watt (400W) EPS system offers increased power for mid-range high-revving racing engines. This version is ideal for boats powered by Mercury Racing 2.5L, S3000, SST-120, F1, F2, Optimax SST-200XS, 300 Drag, or OMC V6 2-Stroke engines. It strikes the perfect balance between assist force and steering feedback, making it ideal for competitive drivers who require tight cornering, fast recovery from chine walk, and superior tracking through rough conditions.
The 600-Watt (600W) EPS system delivers maximum torque and steering assistance. Designed to manage the steering loads from Mercury APX 200 HP, 250 HP, and 360 HP 4-Stroke engines, or even classic OMC V8 2-Strokes, the 600W model ensures stable, responsive steering at any speed. This system is ideal for circle boat setups or heavy-duty race applications where power steering is a critical safety and performance factor.

What’s in the EPS Kit?

Each EPS system comes complete with the following components engineered for durability and precision:

A motor-specific mount for securing the electric assist motor
Two adjustable steering shafts
A set of M10 x 20mm flat head cap screws (Qty: 4) for motor mounting
A pair of M8 x 20mm hex head cap screws (Qty: 2) for the ECU
The Electronic Control Unit (ECU) that manages input signals
A high-torque EPS motor
A wiring harness and a wiring connectors kit to link the entire system

These kits are engineered to integrate with your boat’s existing steering layout, with only minor adjustments necessary to accommodate the mount and shafts.

Preparation for Installation

Before beginning installation, it’s essential to download and review the full instruction manual that includes wiring diagrams and installation illustrations. Check all electrical connectors to ensure that rubber gaskets are fully seated to prevent moisture intrusion.

If needed, gently press them in using a flathead screwdriver. Make sure your existing steering cable and pulley system is in good condition, as the EPS is designed to supplement, not replace, mechanical components.

ECU Mounting

Choose a secure and protected area within the cockpit or hull compartment to mount the Electronic Control Unit (ECU). This location should offer easy access for future diagnostics while remaining isolated from water spray or vibration-prone surfaces. Using the provided M8 hardware, fasten the ECU securely. Ensure the unit is oriented properly to avoid wire stress and interference.

Motor and Mount Installation

Next, prepare the motor mounting system. The EPS motor must be mounted firmly to absorb torque without flexing. The provided mount may need minor modifications to fit your hull or steering tray configuration. Once aligned, secure the motor to the mount using the M10 screws. Tighten the hardware evenly to prevent binding or misalignment.

Steering Shaft Installation

The EPS kit includes two steering shafts, which serve as the mechanical link between the motor and your cable system. Adjust the shaft lengths and angles to ensure smooth operation, avoiding tight bends or misalignment with the existing pulleys. Once fitted correctly, secure the shafts to the motor using the supplied hardware. Check for free movement throughout the entire steering range before proceeding.

Wiring the EPS System

With the mechanical components in place, it’s time to wire the system. Connect the EPS motor to the ECU using the supplied wiring harness. Each wire is color-coded for easy reference:

Red wire connects to the battery positive (+)
Black wire connects to the battery negative (-)
White wire activates the LED diagnostic light
A separate line connects to a switched 12V ignition source

Route and secure all wiring using zip ties and protective loom. Avoid routing wires near hot engine parts or sharp edges. Coil and secure any unused wires, such as a blue wire on some models, in a dry location.

System Activation and Diagnostic Test

With everything connected, turn the ignition key to activate the system. The EPS unit should power on, and the diagnostic LED will flash once for about one second before turning off. This indicates proper system operation. If you observe different flashing patterns or no light at all, refer to the diagnostic codes provided in your kit manual.

Final Checks and Compliance

Before hitting the water, double-check all hardware connections and wire routing. Make sure nothing is loose or exposed. Retain the original packaging until installation is fully confirmed. This EPS system is engineered for performance marine use and should be installed by experienced technicians.

Always ensure your setup complies with local, state, and federal boating regulations. Any modification to this EPS kit outside of recommended configurations may void your warranty and could compromise safety or legality.

If you need additional support or want to view the full illustrated manual, download below or contact Mike@BuckshotRacing77.com or +1-714-697-1716.

This guide will help ensure your Electronic Power Steering system is correctly installed for peak performance, safety, and control in any racing environment.

Download the PDF install guide below!