Upgrade Your Rhino: Electric Fuel Pump Conversion

Many owners of the capable Yamaha Rhino 660, particularly those with higher mileage on the original powertrain, will likely have experienced the frustrations associated with the stock vacuum-operated fuel pumps. With upwards of 16,000 miles, it's not uncommon for these units to fail, and even when functioning, they are notorious for inconsistent fuel flow. The sheer agony of repeatedly trying to prime the system after running out of fuel is a memory many Rhino owners would rather forget. Fortunately, there's a robust and economical solution: converting to an electric fuel pump. While pre-made kits exist, they often come with a hefty price tag. This guide will walk you through a DIY conversion, costing around £50, significantly less than a replacement Yamaha vacuum pump, and offering a substantial improvement in reliability and performance.

Why Switch to an Electric Fuel Pump?

The primary advantages of an electric fuel pump over a vacuum-operated one are:

• Consistent Fuel Flow: Electric pumps deliver a steady and reliable supply of fuel, regardless of engine vacuum.
• Easier Priming: No more hours spent trying to get fuel to the carburettor. Electric pumps prime themselves quickly.
• Improved Performance: A consistent fuel supply can lead to smoother running and better overall engine performance.
• Reliability: Electric pumps are generally more durable and less prone to failure than vacuum-operated units.
• Cost-Effectiveness: As demonstrated, a DIY conversion can be significantly cheaper than purchasing a premium kit or even a new OEM vacuum pump.

Understanding the Carburettor's Needs

A critical consideration for this conversion is the fuel pressure requirement of your Rhino's carburettor. Most carburettors, including those found on the Rhino 660, can only handle approximately 2-3 psi. Exceeding this pressure will lead to the carburettor flooding the engine, resulting in poor running conditions and potentially damaging the mixture. Therefore, a pressure regulator is an essential component of this conversion.

Essential Components for the Conversion

To undertake this project, you will need the following parts and tools:

Parts List:

• Electric fuel pump (16-gauge red, yellow, and black wires)
• 6 inches of 5/16" fuel line
• Automotive relay (e.g., a Bosch-style 4-pin relay)
• Fuse holder and a 3-amp fuse
• Wire nut or small quick-splice connector (Note: The provided quick-splices in the example were too large, necessitating a wire nut.)
• Fuel pressure regulator (more on this later)
• Self-tapping sheet metal screw
• Electrical butt connectors
• Electrical ring terminals
• Electrical spade terminals (split spade terminal is useful)
• Assorted zip ties
• Electrical tape

Tools List:

• Basic hand tools (wrenches, sockets, screwdrivers)
• Wire strippers
• Wire crimpers
• Pliers
• Socket for removing pump mounting bolts (5/16")

Step-by-Step Installation Guide

Before you begin, ensure your Rhino is parked on a level surface and the engine is cool. Disconnect the battery to prevent accidental short circuits.

1. Accessing the Fuel Pump

The first step is to gain access to the original fuel pump. This typically involves:

• Removing the seats.
• Removing the engine cover.
• Lifting the Rhino's bed.
• Opening the hood.

2. Disconnecting the Old Fuel Pump

With access gained:

• Carefully disconnect the fuel lines from the original vacuum fuel pump.
• Locate the vacuum line that runs from the engine's intake manifold to the old pump. Disconnect this vacuum line at the engine side. You can leave the line attached to the old pump for now.
• Using a 5/16" socket, remove the two bolts securing the old fuel pump to its mounting bracket. Keep these bolts, as they might be reusable. Remove and set aside the old pump.

3. Mounting the New Electric Fuel Pump

One of the pleasant surprises in this conversion is that many electric fuel pumps are designed to mount directly to the existing bracket. Check the orientation of your new pump and ensure it's installed the correct way around. The example shows the pump bolting up with a slightly unusual angle, but functionality is key.

4. Wiring the Electric Fuel Pump

This is the most intricate part of the conversion. We'll break it down by component:

4.1. Powering the Pump

• Take a length of 16-gauge red wire. Start on the passenger side of the Rhino, near where the fuel pump is mounted.
• Thread this wire through the tunnel that runs alongside the engine, pulling it through to the area under the hood.
• Route this wire carefully towards the battery box, securing it with zip ties as you go to keep it tidy and away from moving parts.
• At the pump end, trim the wire and attach a butt connector. Connect this to the red wire of the new electric fuel pump.
• At the battery end, strip the wire and connect it to the fuse holder. The other end of the fuse holder will connect to the relay.

4.2. Grounding the Pump

• The electric pump requires a good ground. Take a length of black wire.
• Trim the black wire from the electric fuel pump. Attach a split spade terminal to this wire.
• Locate one of the pump's mounting bolts. Loosen it slightly, place the split spade terminal between the bolt head and the pump body, and then re-tighten the bolt securely. This provides a direct ground to the pump's mounting point.

4.3. Wiring the Relay

Relays are essential for controlling the high current draw of the fuel pump and preventing damage to your ignition switch. Here's how to wire it:

• Relay Pinout (Standard Bosch-style):
• Pin 30: Constant Battery Power (from the battery, via a fuse)
• Pin 87: Switched Power to the Fuel Pump
• Pin 85: Ground for the Relay Coil
• Pin 86: Trigger Signal (from ignition source)
• Power Feed to Relay: Take another length of red wire. Connect one end to the positive (+) terminal of your battery using a ring terminal. Route this wire to your desired relay mounting location. Attach a female spade connector to the other end.
• Ground for Relay: Take a length of black wire. Connect one end to the negative (-) terminal of your battery using a ring terminal. Route this to the relay location and attach a female spade connector.
• Connecting to the Pump:
• Connect the red wire from the pump (which is already connected to the fuse holder) to Pin 87 on the relay.
• Connect the red battery supply wire (via the fuse holder) to Pin 30 on the relay.
• Connect the black ground wire (from the battery) to either Pin 85 or Pin 86 on the relay.

4.4. Triggering the Relay

The relay needs a signal to activate the fuel pump only when the ignition is on. This prevents the pump from running continuously and draining your battery.

• Locate the starter solenoid. You'll see thick battery cables and several smaller wires.
• Carefully strip away some of the black tape from the smaller wires to expose them.
• Identify the small yellow wire with a blue stripe. This wire typically has power when the ignition key is turned to the 'ON' position.
• Connecting the Trigger Wire:
• Measure a suitable length of yellow wire to run from the solenoid to your relay location.
• Attach a female spade connector to one end of this yellow wire.
• Method 1 (Wire Nut): Cut the yellow/blue striped wire at the solenoid and strip both ends. Place these ends and the new yellow wire into a wire nut and secure tightly.
• Method 2 (Quick Splice - if suitable): If you have a properly sized quick-splice connector, carefully attach it to the yellow/blue striped wire at the solenoid. Then, insert the new yellow trigger wire into the connector and crimp it firmly.
• Connect the other end of your new yellow trigger wire to the remaining empty terminal on the relay (either Pin 85 or 86, whichever wasn't used for the ground).

5. Testing the System

Before finalising everything, it's crucial to test the wiring:

• Double-check all connections.
• Ensure the fuse is installed in the holder.
• Turn the ignition key to the 'ON' position. You should hear the relay click.
• Turn the ignition key to 'ON' again. The electric fuel pump should now run. Do not leave it running for more than a few seconds at this stage, as there's no fuel flow yet.

6. Connecting Fuel Lines

Now, let's connect the fuel lines:

• The fuel line coming from the fuel tank (the supply line) should connect to the inlet of the new electric fuel pump. Often, this is the lower port.
• Use the 6 inches of new 5/16" fuel line to connect the outlet of the electric fuel pump to the fuel inlet on your carburettor. You may need to remove the existing fuel line that connects to the carburettor's fuel tee.

7. Installing the Fuel Pressure Regulator

This is a critical step to prevent over-pressurisation of your carburettor.

• DIY Regulator: A clever way to create a rudimentary pressure regulator is to use the old vacuum pump in reverse.
• Locate the fuel line coming from the carburettor that used to go to the vacuum pump. Cut this line in half.
• Install the old vacuum pump into this line. Connect the fuel line coming from the new electric pump to the right-angle fitting on the old pump. Connect the straight fitting on the old pump to the carburettor side of the cut line.
• Important: Ensure the flow direction is correct. Fuel from the new electric pump should enter the old pump via the right-angle fitting and exit towards the carburettor from the straight fitting. If installed incorrectly, all fuel will return to the tank, and none will reach the carburettor. Verify fuel flow before proceeding.

8. Addressing the Vacuum Port

This is a vital step that many overlook. The original vacuum pump relied on a vacuum source from the intake manifold. When you remove the old pump, this port on the intake manifold is left open. If not sealed, it will cause a vacuum leak, and the engine will not run correctly.

• Locate the vacuum port on the intake manifold where the old pump's vacuum line was connected.
• Using a small self-tapping sheet metal screw, carefully plug this vacuum port. Screw it in just enough to create a seal.

9. Finalising the Installation

• Neatly secure all wiring using zip ties, ensuring they are routed away from heat and moving parts.
• Tidy up the relay and wiring connections, perhaps wrapping them in electrical tape for protection and a cleaner look. Mount the relay securely in a convenient location.
• Ensure the fuel pump is mounted securely and oriented correctly.

Final Checks and Benefits

With all the connections made and components secured, you should now have a fully functional electric fuel pump system on your Yamaha Rhino 660. The benefits are immediate and significant:

• No More Priming Hassles: Forget the hours spent trying to get fuel to the carb after it runs dry.
• Consistent Performance: Enjoy smoother engine operation and a more reliable power delivery.
• Increased Reliability: You've replaced a weak link with a more robust system.
• Cost Savings: You've achieved a substantial upgrade for a fraction of the cost of premium kits.

This conversion is a highly recommended upgrade for any Rhino 660 owner looking to enhance the reliability and performance of their vehicle. It's a rewarding DIY project that pays dividends in terms of reduced maintenance headaches and an improved riding experience.

Frequently Asked Questions (FAQ)

Q1: Will this electric fuel pump work with my carburettor?

As long as your carburettor is designed for low fuel pressure (typically 2-3 psi), this conversion should work. The inclusion of a pressure regulator is crucial.

Q2: What happens if I don't use a pressure regulator?

Without a pressure regulator, the electric fuel pump will likely deliver fuel at a pressure too high for your carburettor, causing it to flood the engine and run poorly.

Q3: Can I use a different gauge wire?

It's best to stick to 16-gauge wire or thicker for the main power and ground connections to handle the current draw of the fuel pump safely.

Q4: Where is the best place to mount the relay?

Choose a location that is dry, protected from the elements, and easily accessible for maintenance. Near the battery or fuse box is often a good choice.

Q5: What if the pump doesn't run when I turn the key?

Check all your wiring connections, especially the trigger wire at the solenoid and the relay connections. Ensure the fuse is good and the battery has a charge. Verify the relay is functioning by listening for the click when the ignition is turned on.

Q6: Do I need to seal the vacuum port on the intake manifold?

Yes, absolutely. Leaving this port open will create a vacuum leak, preventing the engine from running correctly. A small self-tapping screw is usually sufficient.