Replacing Cbr 600 F4i Fuel Pump: A Step-By-Step Guide

The Honda CBR 600 F4i is a fuel-injected motorcycle. If your CBR 600 F4i is not starting, it could be due to a faulty fuel pump. Before replacing the fuel pump, you should check the battery, fuel filter, spark plugs, and fuel pressure regulator. If these components are functioning properly, then you may need to replace the fuel pump.

To replace the fuel pump on a CBR 600 F4i, you will need to remove the fairings, seat, and airbox. You will also need to drain the fuel tank or siphon out as much fuel as possible. Once the tank is removed, you can access the fuel pump and hoses. It is important to place rags or towels under the bike to catch any leaking fuel. The fuel pump mounting bolts can then be undone, and the pump can be withdrawn from the tank.

When installing a new fuel pump, it is crucial to replace the crush washers on the fuel line banjo bolt and torque it to the correct specifications. Additionally, ensure that you use a cold engine to reduce the risk of fire during the procedure.

Testing the fuel pump

Step 1: Check for Blockages and Restrictions

Before conducting any tests, it is important to ensure that the fuel pump is not blocked or restricted in any way. Remove the fuel tank and inspect the pump, along with the fuel filter and lines, for any signs of blockages or restrictions. This includes checking for debris, dirt, or rust that may be obstructing the fuel flow.

Step 2: Prime the Fuel Pump

The next step is to prime the fuel pump. This involves turning on the ignition and listening for the sound of the pump priming. If the pump is functioning correctly, you should hear it running. If the pump is not priming, there may be an issue with the power supply or a potential blockage, as mentioned in Step 1.

Step 3: Check Power Supply

Ensure that the fuel pump is receiving power by measuring the voltage at the pump connector. With the ignition on, you should have 12V reaching the pump. If there is no power, check the wiring harness, fuses, and relays associated with the fuel pump circuit.

Step 4: Test Pump Pressure

To test the pump pressure, you will need to disconnect the fuel line from the pump. Place a container under the line to catch any spilling fuel. Reconnect the pump's electrical connector and turn on the ignition. The pump should start running, and you should see fuel being pumped out through the disconnected line. If there is no fuel flow, or if the flow is weak, it indicates an issue with the pump's performance, and a potential replacement may be necessary.

Step 5: Check for Leaks

Once you have completed the pressure test, carefully reconnect the fuel line and ensure that all connections are secure. Check the fuel pump, lines, and connections for any signs of leaks. Leaks can lead to a loss of fuel pressure and potential safety hazards.

Step 6: Test Ride

Finally, take the bike for a test ride to assess the fuel pump's performance under normal operating conditions. Listen for any unusual noises, and pay attention to the bike's performance and fuel efficiency. If the bike runs smoothly and efficiently, it indicates that the fuel pump is functioning correctly.

Remember to refer to your CBR 600 F4i service manual for specific details and safety precautions when conducting these tests. It is important to work with a cold engine and take the necessary precautions to avoid any potential fire hazards when working with fuel.

Checking the ignition

To check the ignition on your Honda CBR 600 F4i, you will need to perform a thorough inspection of the ignition system and its components. Here is a step-by-step guide to help you through the process:

Step 1: Visual Inspection

Begin by performing a visual inspection of the ignition system. Look for any signs of damage, corrosion, or loose connections. Check the ignition coil, spark plugs, and all related wiring. If you notice any visible issues, they should be addressed before proceeding.

Step 2: Check Battery Voltage

Ensure that your motorcycle battery is adequately charged. A weak battery can result in slower engine cranking speeds and even cause a lack of spark at the spark plugs. If the battery voltage is low, consider charging it or replacing it if necessary.

Step 3: Check Spark Plugs

Remove the spark plugs and inspect them for any signs of damage or carbon buildup. Make sure the spark plugs are in good condition and that the gap between the electrodes is within the specified range. Refer to your service manual for the correct spark plug gap and replacement interval.

Step 4: Check Ignition Coil Resistance

Use a digital multimeter to test the resistance of the ignition coil. Disconnect the coil from the spark plugs and set your multimeter to the ohms setting. Place the multimeter probes on the primary and secondary terminals of the coil. Compare the measured resistance values against the specifications provided in your service manual. If the resistance is significantly different, the ignition coil may need to be replaced.

Step 5: Check for Spark

Perform a spark test by reconnecting the spark plug wires to the ignition coil and grounding them against the engine. Turn on the ignition switch and manually rotate the engine. Look for a strong, consistent spark across the spark plug gap. If there is no spark or a weak spark, it indicates an issue with the ignition coil or the spark plugs.

Step 6: Inspect Ignition Pulse Generator

The ignition pulse generator plays a crucial role in the ignition system. Refer to your service manual for the procedure to inspect and test this component. It involves measuring the peak voltage at the generator connector and comparing it to the standard value. If the peak voltage is abnormal, it may be due to a faulty ignition pulse generator or a wiring issue.

Step 7: Check Connections and Wiring

Inspect all connections in the ignition system for loose or poor contacts. Ensure that all wires are securely connected and free from damage or corrosion. Refer to the wiring diagram in your service manual to identify any potential issues with the wiring harness.

Step 8: Refer to Troubleshooting Guides

If you are still experiencing ignition issues, refer to the troubleshooting section in your service manual or seek assistance from a professional motorcycle mechanic. They can help diagnose and resolve more complex ignition problems.

Remember to exercise caution when working on your motorcycle's ignition system. Always disconnect the battery before performing any electrical work, and ensure the engine is cold before starting to prevent the risk of fire.

Replacing the fuel pressure regulator

Disclaimer:

If you are unfamiliar or uncomfortable with performing maintenance on your bike, it is recommended that you take your bike to the dealership and have them replace the FPR for you. Damage to fairings, the gas tank, or critical internal parts may occur if you are careless. In addition, the risk of fire in the following procedure is very high as fuel may be spilled on your bike and yourself. Please perform the FPR swap with a cold engine to lessen the risk of fire.

Part Number 16740-MBW-J32. Roughly $65 at your local dealership.

It regulates your fuel pressure going to your injectors. Most modern fuel-injected bikes run a fuel pump in the tank and run much more fuel than is needed to the fuel rail. A regulator keeps a certain amount of fuel pressure in the rail and then sends the rest back to the tank. The fuel pump aids the FPR to keep the pressure at a constant 50psi (per service manual). It does this with a spring-loaded diaphragm that controls a valve. The valve, when opened by excessive pressure in the fuel lines, uncovers a fuel line that returns excess fuel to the fuel tank. The vacuum connection is there to help reduce emissions during deceleration. During deceleration, the vacuum connection serves to open the fuel return valve wider, which reduces pressure in the system and prevents excess hydrocarbon emissions due to less fuel being injected as a result of the lower pressure in the system.

The most common issue is the spring-loaded diaphragm in the FPR. When it begins to fail, the excess fuel (being supplied by gravity and the fuel pump) is not returned to the tank. This results in a very rich fuel mixture. Symptoms include:

• Poor MPG (15-30MPG)
• Poor Performance
• Fouled Spark Plugs
• Strong Fuel Odor when the bike is running
• Bogging down
• Stalling
• MAP Sensor Error (2 Flashes)
• Exhaust 'Popping'
• Non-standard and erratic engine temperatures
• Cool Exhaust Gas Temperatures
• Gas in Oil
• Difficult to start
• Low/Erratic idle speed

How to replace it:

If you don't want to take your bike to the dealership, here is a step-by-step guide.

Tools:

• QTY 1: Fuel Pressure Regulator: Part 16740-MBW-J32 (Not 16740-MBW-J31. J31 was superseded by J32)
• QTY 1: O-Ring/Gasket. Part Number 16741-PG7-005 (Note: Sometimes the gasket is included. Check with your dealer)
• QTY 1: 5mm Allen Screw - To Remove Fairings
• QTY 1: 6mm Allen Screw - To Remove Gas Tank
• QTY 1: Phillips Head Screwdriver - To Remove Air Cleaner/Box (Optional, but recommended)
• QTY 1: Ratchet Wrench
• QTY 1: 8mm Socket - To Remove upper fuel tank and the FPR itself
• QTY 1: 10mm Socket - To remove the Seat
• QTY 1: 17mm Socket - To drain Fuel Tank (Optional)
• QTY 1: Golf Tee - To plug the Fuel Return Hose
• QTY 1: Gas Can - To Drain tank (Optional)
• QTY 2: Bungee cords - To hold your gas tank (You do not need to remove the tank)
• QTY Lots: Old Bath Towels

The Easy Part:

Step 1: Remove Fairings.

Step 2: Remove the seat.

Step 3: Remove ECU (Optional, But highly recommended)!

Step 4: Prop up the tank with your bungee cord.

Step 5: Remove Airbox (Optional, but you'll get a ton more room to work with).

The Hard Part:

Locate the Fuel Pressure Regulator and the hoses. They are on the clutch side. If you have a small enough ratchet wrench, there is no need to take off the throttle bodies.

The Messy Part:

Step 6: Place your towels under your bike. The best location for them to go is just in front of your kickstand. Again, make sure your engine is cold!

Step 7: Remove the Fuel Return Hose and quickly stick your golf tee in there. Fuel will pour out when you disconnect it.

Step 8: Remove the vacuum hose (if you can reach it. If not, do it once the old FPR is off).

Have your New FPR close to you. You don't want to be searching for it after you remove your old FPR.

The Fun Part:

Step 9: Remove the FPR with your 8mm Ratchet. Notice how the FPR sits flush against the fuel rail. As soon as you start unscrewing it, fuel will start dripping out. Work quickly! It's just going to dribble out, it's not going to get crazy or anything.

Step 10: Replace your FPR and torque to 7ft-lbs. Do not reuse your o-ring. If step 10 takes a long time to complete, don't fret. The fuel will stop dribbling out once the fuel is exhausted in the fuel rail.

Reassemble your bike in reverse order. You should immediately notice a difference once you start her back up and take her for her first ride. Note that it may take longer than normal to start since the fuel in the rail was depleted.

Locating the fuel pump relay

To access the fuel pump relay, you will need to remove the rear plastic of the bike. Underneath the plastic, you will find two relays, with the fuel pump relay being the one closer to the front. This relay is responsible for controlling the power supply to the fuel pump, and it is important to ensure that it is functioning correctly to maintain the fuel pump's operation.

Once you have located the fuel pump relay, you can proceed to test or replace it as needed. It is recommended to refer to the bike's service manual or seek assistance from a qualified technician if you are unsure about the procedure.

Additionally, it is worth noting that there are other components that can affect the fuel pump's operation, such as the ignition switch, wiring, and various sensors. Therefore, it is essential to perform thorough diagnostics and refer to the appropriate repair manuals or seek professional assistance when dealing with fuel pump-related issues.

Removing the fuel tank

To remove the fuel tank of your CBR 600 F4i, start by siphoning out as much fuel as possible from the tank. If you are swapping out the whole tank, remove the cap from the tank so that you can keep using the same key. Next, remove the fairings to expose the tank and its mounting points. You won't need to remove all the fairings, but this will depend on the year of your bike. Undo the mounts for the tank and prop it up with something.

Place rags over the bike and remove the wires and hoses, making sure you know where they came from. The rags will catch any fuel that leaks out. Undo the mounting bolts for the pump and withdraw it from the tank.

If you are removing the whole tank, you can tilt or lift it enough so that you can see the fuel link and the banjo nut. Tilt the tank so that the gas is below the pump opening to avoid spills. Then, take out the banjo nut to remove the fuel line. Thread the banjo nut back into the opening to act as a plug and prevent fuel spills. Place the tank on cardboard or rags to prevent scratches.

Installation is the reverse of the removal process, but make sure to replace the crush washers on the fuel line banjo bolt and torque it to the correct spec.

Frequently asked questions