How To Test Motorcycle Fuel Pump Without Damaging Any Parts?


How To Test Motorcycle Fuel Pump

A faulty fuel system can cause significant damage to you or your motorcycle. Are you facing difficulty while testing the fuel pumps? In this guide, you’re going to read how to test motorcycle fuel pumps effortlessly. 

Undoubtedly, the riding comfortability and smoothness primarily depend on how your vehicle’s fuel pump works. And when it comes to motorcycle fuel pumps, it becomes even more crucial. If you have a motorcycle, you need to take care of the fuel pump at regular intervals. Why? The performance and long riding efficiency primarily depend on the fuel pump.  

So, it is mandatory to check your fuel pump. Sometimes, it gets more challenging to test and fix the issue. But if you know some basic things, you can get the job done. To eradicate the hassle of checking and resolving problems, keep reading the step-by-step guide and making it more fun.

In my point of view, I personally found these steps helpful. So I am writing about this.

14 Steps To Test Motorcycle Fuel Pumps: The Easiest Way

What does a fuel pump do? Well, it helps to shift the fuel from the fuel tank to the carburetor. Sometimes, it can move the oil to the fuel injector. So it is crucial to inspect the power pump conditions after a few days.

But many of us don’t comprehend how to test motorcycle fuel pumps well-handed. In this writing, you’re also going to see the bit by bit in-depth solution on how to bench test on a motorcycle.

Step 1-: Verify The Problem Deeply

Firstly, you need to be aware of the problem. Plus, you must verify or identify the troubles. But how to realize? It is a simple and less time taking operation.

Put your ear near the fuel tank and keep it for a while. Then turn the assistant key in the “ON” position. If you hear a euphonic sound, the fuel system works perfectly. If you hear rasping noise, you need to replace the old fuel pump.

Step 2-: Turn Off The Machine

The next step is to close the engine off. If you are just off your motorcycle, the exhaust system is hot. So immediate action can be dangerous for you. This is why, before removing the fuel tank, you need to turn off the bike for a few minutes. It will help you to work smoothly.

Step 3-: Remove The Fuel Tank Bolt From The Upper-Position

Before fixing or testing the fuel pump of your motorcycle, remove the fuel tank first. By doing this, you can feel flexibility on your testing task. If not, you have to feel the hardship. However, it helps you a lot to find the wires that are leaving the fuel pump. If you find the fuel line goes into the fuel tank, it is ok.

Step 4-: Disconnect The Fuel Line

It’s a very crucial thing to disjoin the fuel line from the tank. Now make sure the line is stagnant and has no pressure inside. So be careful and cautious. Take a thick cloth or gray plastic ears together and then pull hard. Do some things for the other side.

If everything looks fine and cool go for the next. Take a tester to remove these two. If the engine doesn’t start and the pressure is zero, there is a problem with the fuel pressure.

Step 5-: Remove The Fuel-Filter

Now, you need to extract the front side fuel filter cautiously. Here you can’t make any mistakes. Otherwise, the filter and fuel tank will be damaged. To do this, you can come underneath and work by sitting down.

By doing this, you can safely aside the filter. The additional issue might come to an end. During the filter removing sessions, keep it in mind to save your body from a muffler or exhaust system.

Step 6-: Check The Fuel-Pressure

After removing the fuel filter safely, check the fuel pressure and observe it sensitively. At this stage, you need to start the bike. Then take a quick note. If you see the fuel pressure ranges within 41 to 46 Psi.

Now, look at the pressure consistency. If the pressure is the same even if you allow the bike some throttle, you need to understand the fuel pump is working appropriately. Of course, the range of the pressure can be lower or higher. If it happens, you have to understand there is something wrong.

Now a question comes out. What should you do if the fuel pressure is low? Not a big deal, you know. It’s easy. You need to replace the fuel pressure regulator along with the pump.

Step 7-: Check Fuel Volume-Keenly

There are lots of bikes that produce enough pressure,  yet they cannot create sufficient volume. Here the fuel pump volume test is obligatory. In most cases, you can measure the ultimate volume with a fuel pressure gauge.

Here you need to connect the gauge and place the bleed end of its hose into a fresh container. Now arouse the pump for a while (around 15 seconds) without activating the engine. Automatically, the pump should provide a pint of fuel at this time. You can also communicate with the expert to know the exact procedure and information.

Step 8-: Connecting The Fuel Gauge

You can check fuel conditions by connecting a pressure gauge with the pressure port. It is located on the engine. Before doing this, it’s recommended that you disconnect the fuel line from the engine, put a cloth around the port, and wear safety goggles. Here you can check the fuel pressure.

Then you need to extract the port’s cap that covers the port and connects the gauge tightly. After that, turn the assistant key on. If you see the fuel pressure is zero, understand there is a problem. If you don’t identify where the problem occurs, check all the different systems.

Step 9-: Check The Relay

If you feel the problem with the fuel pump system, it is better to check the relay. The relay operates the fuel pump in an easy way. Before doing this, replace the old relay with a new one. But remember, it should be the same type and air conditioning relay.

Now, set the old one up next to the new one. This time turn the assistant key on and check the fuel pressure. If it shows no pressure, the fuel system has something wrong.

Step 10-: Observe The Current Curve With An Oscilloscope

This process is advanced. If the ex-method is not enough for you, you can go through this advanced process. Scientifically, it is one of the most fruitful methods to test the fuel pump.

Before checking with this, take an oscilloscope and a low amp clamp probe. After connecting the probe to the pump power, it will transmit a waveform. And you will see it in the oscilloscope display.

In general, the characteristic of a good pump is that it will produce even “humps” like charts. If it happens, then the fuel pump is in its suitable condition. But if you see an uneven or jagged curve, it is expected to understand that the pump has problems.

Step 11-: Take Help A Higher-Grade Scan-Tool

This process also falls into the advanced method. Nowadays, there are some advancements as well as special tools available. They allow you to test the fuel pump remotely whether the fuel system is sound or not.

You can effortlessly identify the problems with them. Here pressing a couple of buttons is required to activate the fuel pump. At last, you will understand the trouble.

Step 12-: Take A Battery And Unplug The Fuel Tank Hoses

This method is amazingly incredible. Take out the fuel pump from its place. There are two hoses that help to transfer the fuel from the tank to the carburetor. Also, there are two leads to set up with the battery. To test with this method, you need to do:

First, take two pots or standard-size containers. Then fill one of the containers with water. Now keep the left hose into the watery container that is considered as a fuel tank. And place the other hose in an empty container that has been compared to a carburetor or fuel injector.

After that, attach the leads to the battery. Now you can see the real scenario. If the water of the container which is considered to be a fuel tank supplies the water into the empty one, the fuel pump works appropriately. If not, you can go for a new one.

Step 13-: Connect A TuneECU

Fundamentally, it is a technical system to test or identify the errors of a fuel pump. With a TuneECU, you can diagnose motorcycle fuel pump error and find out motorcycle fuel pump symptoms. Moreover, it is built to test the upgraded motorcycle’s fuel pump like the Mitsubishi motorcycle fuel pump.

If the fuel pump is correct, you can’t hear any sound after connecting the electrical connector under the tank. But if the fuel pump has problems inside, you will listen to the pump-priming.

Step 14-: Take A Multimeter With A DC Voltage Unit

You can check the pump manually. To do this, you need to take or grab a multimeter. Before doing this, remove the three Philips head screws. After that, you can see a connector consisting of five specific pins. Now check out the fuel level and grab the multimeter with a DC voltage.

Here you can find two wires: red and black. After setting up the wires, you need to set it to the DC voltage. Now ground your black test lead in the connector pin and turn the key on the right side. Then ground your red test lead. If you see any voltage, you have to understand the fuel pump works great. Else, there will be an issue, and you need to change the older pump.

5 Common Symptoms That Tell You The Fuel System Is Dead:

A motorcycle offers a more blissful riding experience than any other vehicle. So monitoring its internal and external parts is mandatory. A defective fuel pump system can damage a lot. And if it is at the fuel pump then there is no option to skip. Anyway, this problem must be handled and resolved by any means.

But what are the main symptoms to understand the issues? Let’s look at some major lists.

1. Poor Performance Under Light-Load

Usually, motorcycles can hold heavy-load efficiently. But when the fuel pump gets sabotaged, it can perform underscore. To get perfect acceleration and control, the fuel system needs to be perfect. Moreover, you may feel insecure or unstable riding most of the time. If these events occur, then it must be understood there is a problem with the fuel pump.

2. Low Gas Mileage

It can happen by many things. But the real cause happens if the fuel pump doesn’t work perfectly. Ever and anon, the fuel pump regulator doesn’t work perfectly. For this reason, it can’t transfer the oil into the carburetor at a minimum flow rate. Consequently, the fuel will be ignited or may exit through the exhaust.

3. Starting Problem

In most cases, when the fuel pump relay can’t run efficiently, it is common that the vehicle will not start. As a result, the engine is slow to operate and produces less power. Sad but true, most often the engine doesn’t run at all. In this case, you must repair or replace the new pump instantly.

4. Increase Engine Speed Suddenly

Besides engine failure or starting problems, it is possible to increase engine speed. If you feel this problem, surely the fuel pump is not okay. This problem can’t be ignored. If, however, you ignore this problem, you may have to face danger. So be careful about this and fix the issues ASAP.

5. Feel The Whimpering Noise On The Fuel Tank

This is a major but common symptom that makes it easy to comprehend that the fuel pump is not in its normal character. When the fuel pumping system is right, you never listen to any raspy sound or noise. But most failed or worn fuel tanks create a whining noise suddenly.

How To Perform A Bench Test Of A Motorcycle Fuel Pump?

In this case, you need to set up the fuel pump gauge. So take a 6mm line and set it up to a bucket with fuel in it. Then liquidate this gauge in the fuel partially. But remember not to bend it with the fuel pump arm. It may cause more damage. Here you can only clip the line onto the soldering joints.

But to complete this process, you have to be aware and cautious. Don’t touch the gas. Make sure you collect fire extinguishers for safety. Take a machine that has a mixed boom and then plug it in at the wall socket. If you see the water come through the line into the bucket, understand it is alright. This way you can compete on your bench test.

Frequently Asked Questions (FAQs):

How Long Do Motorcycle Fuel Pumps Last?

A fuel pump is considered the most crucial part of your vehicle. But many of us don’t know about life expectancy. It varies from motorbike to motorbike. Also, it depends on maintenance and care. So it is obligatory to know the life expectancy of a fuel pump.

There are lots of motorcycles nowadays. But on average, the least life expectancy of any fuel pump is around 100k miles or even more. But with proper and well-maintenance, it can last more than 200k miles.

Can A Motorcycle Fuel Pump Read 100 Ohms Resistance?

A motorcycle fuel pump can reach around 60 Ohms to 80 Ohms respectively. So the average value of ohms that read a fuel pump is seventy ohms. If it can’t count this value, the fuel pump has a problem.

When it reads 0 ohms, understand the coil falls and your relay doesn’t work. Counters, if it reads unlimited ohms, understand the coil may be unclosed.

How Do You Fix A Fuel Pump Without Replacing It?

You can do this work with keep in mind some general phenomena including:

  • Using a fuel pressure gauge is a simple, unique process, and tremendous alternative solution to test any fuel pump. In this case, you need to take two hoses and a multimeter.
  • Provide some pressure from outside and examine deeply. If your fuel system is bad, it doesn’t create any pressure. Or it may produce more pressure than average. 
  • Maintaining the engine’s temperature or heat.

How Do You Check A Fuel Pump Without A Gauge?

It’s easy. Firstly, disconnect the hose which is coming from the pump and supply oil to the filter. Then block the passage of the hose compactly. You can use your finger here. Next, start the motorcycle and monitor deeply. If the fuel pushes your finger hard, it means the fuel pressure is right. If not, you can go for another.

Final Touch:

No one in the world wants the worst driving experience. In most cases, the main damage happens for the worst fuel pump. If the fuel pump doesn’t work perfectly, there is a high chance of having an accident. It also ruins the drivability and transmission progress. This is why testing a fuel pump is vital. 

But before checking properly, you need to know the proper guide about testing. However, to make this kind of work hassle-free, the step-by-step guide on how to test motorcycle fuel pumps has been described.

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Ahsan Ullah

Hi guys, This is Ahsan Ullah. I have been riding motorcycle for more than 15 years. In this long period, I have experienced a lot of things about bike riding. Now I am trying to share my experience with you on this website.

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