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Most Common Problems With Kawasaki Mule Diesel Engine

Most Common Problems With Kawasaki Mule Diesel Engine

Kawasaki Multi-Use Light Equipment vehicle, or also known as Kawasaki Mule, debuted in 1988. However, the category was born even earlier, in 1980. The vehicle had a twin-cylinder engine with a displacement of 454cc.

As a result of upgrades, however, MULEs are now equipped with diesel and petrol engines. Moreover, these engines are durable and robust. In this way, up to six people can travel comfortably.

Kawasaki Mule Diesel Engine

In 2000, Kawasaki introduced the MULE 2510 with a newer engine. It was a 953cc diesel engine with liquid cooling. Aimed to target the customers in the agriculture and mining industry, it was a big hit. Since then, the engines of Kawasaki never failed to impress.

Therefore, today in this article, we are going to highlight those problems. Among them, some are quite common, whereas some are pretty rare.

Common Problems of the Kawasaki Mule Diesel Engine:

Here I’m sharing the 5 most common problems of the Kawasaki Mule Diesel Engine. So without wasting any time, let’s dive in.

1. Throttle Body Issues

A popular issue with the Mule engines is the throttle bodies. There is a possibility that the sensor can be damaged; thus, it may not work. The problem worsens when one bad sensor will force you to replace all of them; quite a costly fate!

A user reported that one sensor became unusable. A cost of close to $2000 was incurred when he tried to get things fixed, which made him mad. Changing all the sensors was the biggest reason for the cost, which did not make sense to him.

However, this issue has an in-depth reason behind it. Per US EPA regulations, the air intake cannot be vented to the environment. Because the air cannot be vented, it remains inside, converting into vapor. After being sucked in and burned, a gum-like substance is left behind in the engine.

It may be possible to solve the problem by doing a routine thorough cleanup. The problematic area can be accessed by removing the inlet hose. An excellent tool to use here is a throttle body cleaner. Kawasaki offers a second option. According to them, the CCV hose needs to be routed to a different location. They sell a kit for this purpose.

2. Problem with the Fuel Pump

Fuel pumps on this engine may occasionally fail. A Kawasaki engine is not supposed to malfunction, but this is indeed the case. In most cases, it is the filters that are to blame.

There is a chance that the oil you use is not 100% clean. Often, this can contain debris, which is a big problem for your engine. Oil filters tend to become dirty quite soon because of the high amount of debris in them. This can lead to fuel pump failure.

According to one user, his 4th fuel pump has failed. As a result of dirt build-up, the filters have turned red, resulting in complications. Within five minutes, the pump failed because the lubricant and coolant had worn off.

Changing the pump system can solve the problem. Modern pumps can save you from misery since they can be serviced. Furthermore, you should replace the filter every 40-50 hours of riding. Ensure the oil is properly filtered as well. An odd solution, right?

3. The Loose Pins of the Harness

The harness also poses a problem. With time, the pins can come loose. Several users have reported the problem, but it has never been resolved.

You may find the wiring harness that connects to the main connector to have loose pins. Unfortunately for you, a new engine can develop this problem. The only way to fix that is to replace the entire thing, a costly fix!

A user says the connector’s wiring harness has been loose since newly bought. He eventually spent about $400 to solve the problem. Besides, the process was labor-intensive as well. Not something you want to experience, right?

The harness can be temporarily adjusted if you can’t afford to replace the harness. Essentially, you need to pull the connections apart and pinch the female pins. A screwdriver is useful for this.

4. Non-Durable Gasket

The gasket of this engine has given a headache to several users till now. They are not durable at all. The leaking and cracking of those gaskets are a routine issue with this engine.

Whenever you see foamy stuff under your oil cap, it means your gasket needs to be replaced. Water or coolant leaks into the oil when you have a leaky gasket. Water has also caused rust problems since oxygen is an excellent rust maker.

As reported by a user, foamy substances were found under the oil cap. Upon further examination, he also found some rust on the head’s side. Upon examination, he discovered a cracked gasket head.

People in the community recommend changing the gaskets when they exhibit problems. For years, the stock gasket hasn’t performed well. It is, therefore, necessary to replace them with aftermarket parts.

5. Loses Power Over Time

Strangely, the Kawasaki Mule Diesel engine tends to lose power over time. Engines are built to serve you over time, and that’s what we generally hope for. This engine can, however, disappoint you.

If you put several hundred miles on this engine, you will see that the performance is drastically different. Suddenly, power is lost. Even though fuel lines and the pump are not damaged, a problem like this is pretty confusing.

Community members are concerned about this problem. According to one user, the engine starts to lose power after hitting roughly 400 hours. Although the decrease was not that noticeable, it became evident when the engine reached 500. Suddenly, the top lost one-quarter of its speed.

What about the solution? According to users, changing the fuel filters and fuel lines has resolved the problem. It appears that they are the leading causes of the blockage. Besides replacement, a thorough cleaning will also help.

Pros and Cons of Kawasaki Mule Diesel Engine:

Here are some Pros and Cons of the Kawasaki Mule Diesel Engine.


  • Quick off the Line: Mule engines gain speed very quickly. Because these engines have higher torque, they can easily accelerate off the line quickly. If you are looking for a drag race with this, you will get a head start.
  • Higher Top Speed: Not only the 0-100-mph performance, but the top speed is also very high. Yes, the speedy acceleration helps, but this engine can hit speed at a very high peak.
  • Powerful: There is a lot of power in this engine. A powerful engine of this caliber can handle any terrain easily.


  • Throttle Body Issues
  • Problem with the Fuel Pump
  • The Loose Pins of the Harness
  • Non-Durable Gasket
  • Loses Power Over Time


You need to purchase an engine even though it comes with some issues at the end of the day. However, once you’re aware of them, you can be ready to get rid of the hassles. I think you won’t be disappointed with the diesel engines of Kawasaki MULE, however. That’s true, even after all the problems we have discussed. Let us know if you have any questions regarding the issues.

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