How To Fix Motorcycle Running Rich Issues?

Studies have revealed that motorcycles can produce as much pollution as big trucks or diesel buses. This happens due to a lack of proper maintenance and using the wrong fuel. Over time, you might also begin to notice that your bike is running rich or lean.

So, how do you fix a motorcycle running rich? If your motorcycle is running rich, you can solve this issue in the following ways: 

• Check and adjust the float height in your bike’s carburetor.
• Adjust the Idle mixture screw.
• Clean the air filter installed on your motorcycle.
• Get your bike’s fuel injectors cleaned.

In this article, we will explain why your bike is running rich and how to fix this issue. So, let’s get started!

Motorcycle Running Rich: How To Fix It

Below, we have explained some common reasons why your motorcycle might be running rich and how you can fix it.

1. Check and Adjust the Float Height in Your Bike’s Carburetor

Look at the picture we have provided above. Here, you will notice a sealed bowl inside a carburetor. This is called the carburetor float. 

It maintains a consistent fuel level in the float bowl by opening the needle valve as fuel is used up. But if the float height in your bike’s carburetor isn’t adjusted accurately, it could cause your bike to run rich. 

Thus, you should follow these steps to adjust the float height in your bike’s carburetor:

• Step 1: Check the standard tuning recommendations in your bike’s owner’s manual to determine the accurate float level for your bike’s carburetor.

• Step 2: Use a “Bikemaster Float Level Gauge” to measure the distance between the float and the ceiling surface on the carburetor body.
• Step 3: Use the gauge to check the current height of the float.

• Step 4: Use a flat-blade screwdriver to adjust the float height until it is in the correct position.

For more details on this process, you can watch this YouTube video.

2. Adjust the Idle Mixture Screw

The screw shown on the left side of the picture above is commonly known as the Idle mixture screw. By adjusting this screw, you can control the amount of air mixed with the fuel in your bike’s engine combustion chamber. 

If you think your bike is running rich, you should rotate this screw counterclockwise 1-2 times until you notice an increase in RPM. This way, you can maintain a balanced air-fuel mixture ratio in your bike’s carburetor.  

However, make sure you don’t turn the screw more than 2 times, or else too much air will enter your bike’s engine.

3. Clean the Air Filter Installed in Your Motorcycle

According to researchers, a clogged air filter can negatively impact your bike’s performance in the following ways:

• Increases fuel consumption.

• Prevent air from entering your bike’s engine.
• Causes the engine to overheat.

So, if your bike shows signs of running rich, you should clean the air filter. Below, we have given the steps you can follow to clean the air filter on your bike.

• Step 1: Unscrew the screws around your bike’s seat to remove the seat cover.
• Step 2: Take some tissue papers and insert them into the four-velocity stacks. This way you can prevent any material from dropping into the engine.

• Step 3: Open the cover of the air filter with your hands.
• Step 4: Check the air filter for trapped dirt and debris.

• Step 5: Then, fill an empty spray bottle with a solution of cold water and dish soap.
• Step 6: Spray this mixture onto the air filter.

• Step 7: Thoroughly clean both sides of the air filter with cold water.
• Step 8: Gently use a wooden stick to remove stuck dirt from the air filter.
• Step 9: Shake off any excess water from the air filter and let it air dry completely.
• Step 10: Apply air filter oil to the air filter and wait for 10 minutes.
• Step 11: Lastly, reinstall the air filter properly on your bike.

For a visual representation of this process, you can watch this YouTube video.

4. Get your bike’s fuel injectors cleaned

Another way you can solve the issue of your bike running rich is to inspect your bike’s fuel injectors and clean them if they look dirty. 

According to a study, your bike’s fuel injectors should maintain an injection pressure of around 1000–1200 bar. This way, the injectors can spray an adequate amount of fuel and maintain the proper air-fuel mixture in your bike’s engine. 

If you notice your bike running rich due to clogged fuel injectors, take it to a mechanic and get the fuel injectors cleaned properly. 

What Are The Key Signs Of A Rich-Running Motorcycle Engine?

Take a look at the information we have provided below. Here, we have listed the common signs you might notice if your motorcycle’s engine starts running rich.

1. While you are driving, your bike will produce a lot of black smoke.
2. You will notice that your bike has become sluggish.
3. Your motorcycle will make choking noises while starting.
4. It will be hard to start your bike while the engine is warming up.
5. The spark plugs in your bike will turn black.
6. You might have to add more fuel to your bike than usual.
7. Your bike won’t perform well at higher altitudes, such as 10,000-12,000 feet.

FAQs

Check out the FAQs we have given below to gain more information on how to fix a bike that is running rich.

Final Words

Overall, if the amount of fuel in your bike’s engine becomes higher than the air during the combustion process, it can significantly affect the performance of your bike.

There are several procedures you can follow to fix this problem. Most importantly, you should figure out the main reason why your bike is running rich. If it is due to a carburetor issue, you should fix the internal components of the carburetor. 

If that does not solve the problem you should clean the air filter and fuel injectors. Plus, you can change the airflow sensors installed on your bike.