Top 5 Kawasaki Mule Pro FXT Problems With Quick Fixes

Kawasaki brought their Mule Pro FXT to the UTV market in 2014. It is, thus, their latest series of 4-stroke engine utility vehicles. Kawasaki promised to introduce their most advanced engine with many high-end features for the Pro FXT vehicle. But has Kawasaki been able to fulfill its commitment? Plus, where would the Mule Pro FXT series stand in the long line of Kawasaki UTVs?

We found a few fundamental Kawasaki Mule Pro FXT problems as we investigated them. It included oil leaks, transmission problems, inconsistency in speed, overheating problems, and issues with the engine. Unfortunately, most of these problems were visible in other Kawasaki Mule vehicles. So, it is disappointing to see that Kawasaki hasn’t fixed them. 

In this article, we will go through the top problems of Mule Pro FXT and their solutions. If you have a Pro FXT or plan to buy it, read this article for a better investment. 

Kawasaki Mule Pro FXT Problems

Top Kawasaki Mule Pro Fxt Problems:

Top Kawasaki Mule Pro Fxt Problems

The Mule Pro FXT series has a significant promise of the best utility vehicle riding experience for riders. However, the vehicle needed to meet its expectations due to many problems. Most of the Mule user forums have massive complaints about its engine, heating, and radiators. 

Crash Hazard Due To Steering Problems:

Crash Hazard Due To Steering Problems

Kawasaki has recalled all of their USA models for Mule Pro FXT from 2015 to 2020. According to Consumer Product Safety Commission (CPSC), these vehicles have serious problems with their steering. They reported that the steering wears out too soon. As a result, riders will lack control over it, which might cause serious safety hazards. 

However, no accident problems have been reported due to these safety hazards and steering problems. Kawasaki recalled the off-road UTV as a safety concern. 


The wear and tear of the steering on Mule Pro FXT is a structural and design fault. So, there’s hardly anything you can do. We suggest you take the motorcycle to a mechanic or official dealer for a complete checkup. You can claim a quick replacement if there’s any problem with the wearing-out steering. 

Inability To Reach The Top Speed And Inconsistency In Speed:

Kawasaki has enabled their Mule series to reach a maximum of 46MPH speed. Unfortunately, Mule Pro FXT rarely reaches the 46MPH speed. In fact, many users have complained that their UTV has failed to reach 15MPH speed even. 

Also, there needs to be more consistency in the speed. So, while riding the Pro FXT, many riders saw the speed going up and down. It resulted in massive dissatisfaction among the riders. Also, it was a major safety hazard due to problematic speed. 

The problem of inconsistent speed and not reaching top speed happens because of worn-out belts. Also, a damaged and clogged fuel filter is responsible for it. 

So, here’re the top solutions for the speed problem. 

Replace The Belt:

The belt driver is responsible for maintaining consistency and combining the front and rear wheels. As it wears out, the UTV loses its speed. So, you must replace the Pro FXT driver belt. It will help you enjoy improved speed. 

The belt will cost you around $125 to $200. Replacing the belt requires a complete knockdown of the utility vehicle. So, you should call a mechanic to fix it. 

Cleaning And Replacing The Fuel Filter:

Cleaning And Replacing The Fuel Filter

Clogs in the fuel filter cause inefficiency in the engine. So, it fails to deliver maximum power output and reduces speed. So, you must check the fuel filter for clogs and try cleaning it. Ideally, you should maintain the fuel filter for every 100-hour ride. 

  • You should find the fuel filter close to the fuel pump 
  • As you open up the pump, you will find the filter with ease 
  • Use gloves to grab the filter and remove it from the vehicle 
  • Then, you may wipe it with a brush and liquid detergent 
  • Also, check the filter for residues and try cleaning it 

Mostly, cleaning the filter will boost the speed slightly. If it continues showing inconsistency, replace the filter. You may choose the Kawasaki 49019-0013 Fuel Filter as a quick replacement option. It costs less than $10 and delivers outstanding performance. 

Problems With The ECU System:

You may sometimes see that your Pro FXT is having issues starting correctly. Some vehicles will start and then shut off automatically. This automatic shut-off may happen immediately or after riding the UTV for a few miles. In the worst scenario, your Pro FXT from Kawasaki won’t start. 

The problem happens because of a faulty Electronic Control Unit (ECU) system. It is a computer-based system and works like the brain of your vehicle. There’re sensors in the Mule engine, and the ECU collects information from these sensors. 

Thus, the ECU controls the engine performance and output depending on the collected data. Things become problematic if the sensors deliver accurate data or the ECU needs to convert it accurately. The ECU will limit the performance of the Mule engine. So, it won’t start. It also causes inconsistency in speed. 

Change The ECU System:

Whether you want to fix the starting problem of the Mule Pro FXT or increase its speed, changing the ECU system will be the best decision. You may also get an ECU tuner to boost its performance. You may integrate your Pro FXT with several performance tuning and upgrading accessories. 

  1. Kawasaki Mule Hour Meter by Moose
  2. Kawasaki Teryx / Mule Resettable Hour Meter

These two performance enhancers are gettable at around $35. You may integrate them with the Kawasaki Mule Pro FXT to boost the ECU performance. You may also delimit the ECU to increase the top speed of your Mule vehicles. 

Fault Code 51:

Although not as common as engine problems or wearing out steering, fault code 51 for Pro FXT is not rare. Fault code 51 refers to the voltage irregularity of the battery. Mostly, the ECU sensor has failed to read the accurate data. Or the battery is delivering inconsistent output. 

As it happens, fault code 51 will keep beeping. If it persists, the ECU will stop working. So, your vehicle will come to a standstill. 

Changing The Battery And ECU:

Changing The Battery And ECU

Depending on the reason for fault code 51, you need to replace either the battery or the ECU. We suggest you check the battery with a multimeter. Connect it with the negative and positive probes of the battery and check the voltage output. 

If there’s inconsistency, you should call a mechanic. If the battery is damaged, change it. It will cost you $50. Plus, the cells may sometimes dry out due to exposure to extreme cold or heat. If it is the cause, try fixing the damaged battery cell. 

You may, sometimes, find the battery is fine. So, test the ECU sensors and get a new one if it is the root of the problem. You will then need to replace the ECU or the faulty sensor to fix the fault code. 

Sometimes, the earthing circuit of coil number 1 may be damaged. So, check it and see if it requires replacement. 

Idling Problem:

Another common problem for all the Mule series utility vehicles is the idling issue. This problem has two different aspects:

  1. As you gas up the pedal, Mule Pro FXT accelerates fast; likewise, a new one 
  2. As you release pressure from the pedal, it doesn’t deaccelerate or reach an absolute standstill position. 

If the problem starts repeatedly, you will experience the engine dying off without any alerts. You will also see continuous sputtering. 

The problem occurs due to carbon buildup in Pro FXT’s throttle body. The carbon development will look like black soot. Also, it forces the throttle blade to close and stop working. 

Clean The Throttle Body And Its Parts:

You must clean the throttle body to eliminate carbon development. It also helps in increasing the speed of the utility vehicle. First, access the throttle body and remove it from the vehicle. Then, use WD-40 cleaner to spray over the entire throttle. Allow the WD-40 cleaner to work on the metal parts for a few minutes. After that, scrub and clean it off with a toothbrush. 

Also, follow these steps:

  • Use your fingers to access the throttle blade of the ECU system. Locate the shaft bearing area and spray the cleaner on it. 
  • Continuously open and close the shaft bearing while cleaning. It helps you remove all the residual development from the shaft and ECU sensors. 
  • Finally, you must test whether the electronic system is working correctly. For this, remount the system and turn on your UTV. If everything is fine, the throttle blade will open. 


Kawasaki Mule Pro FXT has been in the UTV market for only eight years. Yet, its number of problems is on the higher side. Thus, Kawasaki Mule Pro FXT problems are disappointing for the users. If you plan to purchase a used Pro FXT, we suggest you ride it for 20 miles at least. Also, call a mechanic to check it to avoid future issues with the utility vehicle. 

Also, both new and old users must maintain the UTV timely. It boosts performance and removes many inevitable problems.

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