Testing Fuel Pressure On Suzuki Dl650: A Comprehensive Guide

Testing the fuel pressure on a Suzuki DL650 involves several steps. Firstly, it is important to lift and support the fuel tank, placing a rag under the fuel feed hose. The next step is to remove the fuel feed hose and install special tools such as a fuel pressure gauge adaptor and hose attachment between the fuel tank and delivery pipe. With the ignition switched on, the fuel pressure can then be checked and inspected. If the fuel pressure is outside the specified range, certain items such as the fuel pump check valve will need to be inspected. It is important to note that gasoline is highly flammable and explosive, so caution must be exercised during the process. Additionally, proper maintenance of the fuel system, including regular cleaning and replacement of filters, is crucial to ensure the optimal performance of the Suzuki DL650.

Lift and support the fuel tank, placing a rag under the fuel feed hose

To test the fuel pressure on a Suzuki DL650, you will need to lift and support the fuel tank. This will require some care and attention to safety, as you will be working with flammable liquids and gases. Begin by placing a rag under the fuel feed hose. This will catch any spills or leaks and protect the surrounding area. It is important to ensure that the area you are working in is well-ventilated and that no sources of ignition are present.

Once the rag is in place, you can then carefully remove the fuel feed hose. At this stage, you will need to install the special tools required to test the fuel pressure. These include a fuel pressure gauge adaptor and a fuel pressure gauge hose attachment. These tools will need to be installed between the fuel tank and the fuel delivery pipe. With these tools in place, you can then turn the ignition switch on and proceed to check the fuel pressure.

The specified fuel pressure for a Suzuki DL650 is approximately 300 kPa (3.0 kgf/cm², 43 psi). If the fuel pressure is lower than this, you may need to inspect the fuel pump check valve, as well as other relevant components. On the other hand, if the fuel pressure is higher than the specified value, there may be other issues that require further investigation and potential maintenance.

It is important to exercise caution when working with fuel systems. Before removing any tools or disconnecting hoses, remember to turn the ignition switch to the OFF position and release the fuel pressure slowly to avoid any sudden releases of pressure or fuel spraying.

Remove the fuel feed hose and install special tools

To test the fuel pressure on a Suzuki DL650, you will need to remove the fuel feed hose and install special tools. Here is a step-by-step guide on how to do this:

First, lift and support the fuel tank. Make sure you are working in a well-ventilated area, and be cautious as gasoline is highly flammable and explosive. Keep any sources of heat, sparks, and open flames away from the work area. Place a clean rag under the fuel feed hose to catch any spilled gasoline.

Next, remove the fuel feed hose. Disconnect the fuel feed hoses from the fuel delivery pipe and fuel pump. Be sure to wipe off any spilled gasoline.

Now you can install the special tools. The part numbers for the required tools are as follows:

• 09940-40211: Fuel pressure gauge adaptor
• 09940-40220: Fuel pressure gauge hose attachment
• 09915-74511: Oil pressure gauge set

Once the special tools are installed, you can turn the ignition switch on and check the fuel pressure. The fuel pressure should be approximately 300 kPa (3.0 kgf/cm², 43 psi).

If the fuel pressure is lower than the specification, you may need to inspect the fuel pump check valve. If the fuel pressure is higher than the specification, there may be other issues that need to be addressed. Remember to turn the ignition switch to the OFF position and release the fuel pressure slowly before removing the special tools.

Turn the ignition on and check the fuel pressure

To test the fuel pressure on a Suzuki DL650, you will need to first lift and support the fuel tank. Place a rag under the fuel feed hose, then remove the hose and install the special tools (a fuel pressure gauge adaptor and a fuel pressure gauge hose attachment) between the fuel tank and the fuel delivery pipe.

Now, turn the ignition on and check the fuel pressure. It should be approximately 300 kPa (3.0 kgf/cm², 43 psi). If the fuel pressure is lower than this, you will need to inspect the following:

• Fuel pump check valve
• Fuel tank lift-up
• Fuel pump control system
• Fuel injector
• Fuel pressure regulator
• Fuel pump
• Fuel delivery system

If the fuel pressure is higher than the specification, the above items should also be inspected.

Before removing the special tools, remember to turn the ignition switch to the OFF position and release the fuel pressure slowly. Gasoline is highly flammable and explosive, so keep heat, sparks and flames away from the engine.

Inspect the fuel pump check valve if pressure is too low or too high

To test the fuel pressure on a Suzuki DL650, first, lift and support the fuel tank. Place a rag under the fuel feed hose. Remove the fuel feed hose and install the special tools (a fuel pressure gauge adaptor, a fuel pressure gauge hose attachment, and an oil pressure gauge set) between the fuel tank and the fuel delivery pipe.

Then, turn the ignition on and check the fuel pressure. The fuel pressure should be approximately 300 kPa (3.0 kgf/cm², 43 psi). If the fuel pressure is lower or higher than the specification, you will need to inspect the fuel pump check valve.

• Remove the seat, fuel tank side covers, and lift and remove the fuel tank. Removing the entire front-end cockpit will make the job easier.
• Once the tank and side panels are removed, drain the radiator, disconnect the fan and horn, and remove the radiator reservoir under the seat.
• Remove the rocker covers by using a light tap with a mallet to break the gasket seal.
• Remove the spark plugs. You only need to remove one per cylinder if you are not replacing them.
• Remove the two covers on the left side of the crankcase. The lower cover allows access to rotate the crank, and the upper cover provides access to the crank timing marks.
• Use a 17mm socket to rotate the crank anticlockwise until the 'F' mark in the upper inspection hole aligns with the mark on the crankcase. Ensure that both cam lobes on the front cylinder are in Position A. If not, rotate the crank another 360 degrees.
• Insert a feeler gauge and measure the four valve clearances. You are looking for a nice sliding fit without any undue amount of drag.
• Rotate the crank 270 degrees anticlockwise until the 'R' mark appears in the inspection hole. Check that the cam lobes for the rear cylinder are in Position B.
• Measure the clearances for the rear cylinder valves. Record your measurements.
• Based on your measurements, determine which valves need adjusting. The inlet valve gap should be between 0.10-0.20mm (0.004-0.008 inch), and the exhaust valve should be 0.20-0.30mm (0.008-0.012 inch).
• If any valves are out of specification or at the extreme limit, you will need to adjust them.
• Read and understand the valve clearance adjustment procedure before proceeding.
• Rotate the crank until the 'F' mark aligns and the cam lobes are in Position A.
• Remove the camchain guard.
• Take photos of the position of the cams and the count of cam chain rollers between the marks on the exhaust and inlet cams.
• Release the tension on the cam chain to remove the cams. This can be done by removing the nut on the back of the cam chain tensioner and releasing the ratchet on the adjuster mechanism.
• Slacken and remove the bolts on the cam chain journal and remove the journal.
• Remove the cam and use a small magnet to remove the shim bucket and shim.
• Replace the shim with one of the correct thickness, referring to the shim size chart in the Suzuki service manual or using a micrometer.
• Place the new shim on top of the valve, add a drop of oil, and replace the shim bucket.
• Repeat the above steps for the other cams as needed.
• Reinstall the camshaft, ensuring the alignment of the marks on the cam and cylinder head.
• Put some oil on the cam journal bearing surfaces and replace the journal, lightly bolting it into place.
• Tighten and torque the journal bolts and replace the cam chain tensioner to restore pressure to the chain.
• Leave the cam chain guard off for now and turn the crank 360 degrees anticlockwise until the 'F' mark appears in the inspection hole again.
• Check that the marks on the rear cylinder inlet cam and cylinder head are aligned.
• Repeat the valve clearance adjustment procedure for the rear cylinder.
• Once all adjustments are made, turn the crank several times, check the clearances again, and ensure the timing marks are correct.
• Replace the camchain guard, clean the mating surfaces, and replace the rocker head covers.
• Reinstall the radiator, fuel tank, and fairing.

By following these steps, you can inspect the fuel pump check valve and adjust the valve clearances on a Suzuki DL650 if the fuel pressure is too low or too high.

Keep the tank fairly full to avoid condensation

Keeping the tank fairly full is a good practice to avoid condensation in your Suzuki DL650. This is because the water in the air can cause rust in the fuel tank, especially in humid climates. The air space above the fuel allows for condensation, which can then lead to rust. By keeping the tank full, you reduce the air space and help prevent condensation from forming.

Condensation and rust can cause several problems with your bike. Rust particles can get into the fuel system, clogging filters and affecting performance. Rust can also damage the fuel tank itself over time, leading to leaks and potentially dangerous situations.

To avoid these issues, it is recommended to keep the tank fairly full whenever possible. This is especially important if you plan to store your bike for an extended period. Riding regularly can also help prevent condensation and rust, as it allows the fuel to circulate and reduces the amount of time the tank is left stagnant.

Additionally, proper maintenance and cleaning of the fuel tank can help prevent rust. This includes regularly cleaning and replacing fuel filters, as well as using fuel tank treatments or sealers to protect against rust. Keeping the bike clean and maintained can also help prevent corrosion on other parts of the motorcycle.

By following these practices, you can help keep your Suzuki DL650 in good condition and avoid the headaches caused by condensation and rust in the fuel system.

Frequently asked questions