5 Kawasaki FX730V Problems With Solutions

The Japanese company Kawasaki, also known as Kawasaki Heavy Industries, is renowned for producing top-notch tractors, ATVs, aerospace machinery, and engines, among other devices and their parts.

The FX series is one of the brand’s most adaptable and well-liked engine types.

The 4-stroke vertical shaft FX engines are regarded as powerhouses in compact packs. The strong FX engines, which are already popular in the US, have an HP range of 13.2 to 31.4 hp.

And the FX730V, which has 23.5 horsepower, is the engine we’ll be concentrating on in this case.

The FX730V is, without a doubt, a powerhouse and provides Kawasaki professional-grade power to handle any hurdles in landscaping.

But this engine also has several issues that, if not addressed immediately, could have serious consequences. Most customers have complained about various problems, including fuel filter leaks, valve issues, and malfunctioning engines.

In the following post, we will have, therefore, selected the top most discussed problems of the FX730V, which are as follows.

  • Valve issues
  • Leaky fuel filter 
  • Engine won’t start
  • Battery drainage
  • Reduced engine speed

Having a hard time maintaining your patience? Here is a list of the FX430V issues we encountered most frequently. You can see an overview of the FX430V problems and their solutions in the table below(s)

Kawasaki FX730V ProblemsSolutions
Valve issues• Check the valve’s seal or tension
• Clean the cooling system
• Service the valve
Leaky fuel filter• Fix the fuel filter or replace it
Engine won’t start• Replace the spark plug
• Service or replace the carburetor
• Replace the ignition coil if needed
• Clean the fuel
• Change the fuel
• Keep the fuel tank filled
• Check the voltage regulator
Battery drainage• Check and fix the alternator
• Check the voltage regulator
• Tighten the loose cables
• Clean the battery terminals
• Take the engine to the service center in case of parasitic drainage
Reduced engine speedCheck and replace the spark plug
• Clean the carburetor
• Cool down the engine if it is overheated 
• Check and keep the fuel filter clean

5 Common Kawasaki FX730V Problems With Their Solutions

We read through numerous customer reviews before listing the issues with the FX730V engine. 

The majority of customers have attested to the FX730V engine’s high level of performance and robustness. However, some have expressed dissatisfaction with several problems the engine has developed.

We have examined most of these reviews, and based on our findings, we have listed the top 5 issues with the FX730V here.

Continue reading this section to the end if you intend to purchase a FX730V engine. You can be sure it will be worth reading, we promise.

1. Valve Issues

As with any engine, the FX730V can also run into valve issues, and several customers have complained of facing this problem. So, here is our take on the valve issues you may face with this engine, along with their causes and solutions.

Problems in Installation and Modification

Inaccurate settings for valve clearanceInaccurate valve spring installation
• Too tight valve clearance
• The maintenance window is over
• Incorrect insertion of valve spring during the installation
• Lateral bending moment (M) on the valve stem

Machine Problems

Valve seat input or valve guide incongruenceValve seat input or valve guide incongruenceValve guide clearance that is too large
Valve seat or guide re-machining that is non-centricToo much valve guide clearanceToo small guide diameter

Installation Of Worn Parts

Using old, worn valve cottersInstallation of bent valves
Over-reaming during repairsUnilateral support of the valve seat

Some common symptoms of a failed engine valve are as follows.

  • Cold engine start
  • Idling
  • Excessive oil/ fuel consumption
  • Impact loading
  • Exhaust smoke
  • Recessed valves, etc.


Despite being a rugged, long-lasting engine, the Kawasaki FX730V occasionally experiences valve issues. And one of the main reasons for these issues is a lack of maintenance.

Try the following standard self-help troubleshooting methods if the problems are not too serious.

  • Properly check the valve’s seal or tension.
  • Periodically clean the cooling system.
  • Verify the valve’s clearance.
  • Examine the valves for corrosion if necessary.
  • Look for burnt, cracked, broken, or worn-out engine valves.

It can be challenging to diagnose engine valve problems at times. Consequently, if assistance is required, take the engine to a nearby authorized service facility.

2. Leaky Fuel Filter

The fuel filter filters all gas before it reaches the engine to prevent contaminants from entering the mower’s carburetor. However, the engine may present a fire risk if the fuel filter leaks.

Several Kawasaki lawn mowers were recalled because of defective fuel filters. According to reports, the filters put the engine at risk of fire by leaking oil into it.

Kawasaki Motors has received over 100 reports or complaints in this regard.

Therefore, even though no injuries were reported, all owners of Kawasaki lawn tractors or those who use other brands that use Kawasaki engines should know this is a problem.

Possible causes of fuel filter leakage:

  • Incorrect re-installation of the housing cap
  • Incorrect tightening of the fixing screws 
  • Inaccurate installation procedure 
  • Potential holes in the fuel tank, etc.


The first thing to do is STOP USING THE ENGINE if you discover that the fuel filter on your lawn tractor or mower is leaking. Never forget that a leaky fuel filter can cause fire risks.

The next step is to check the fuel filter to look at the issue (s). Then, depending on the issue, you can either fix the fuel filter or buy a new one.

Installing a new fuel filter instead of an outdated one is fairly simple. But if the self-installation option does not feel right, look for a qualified small motor specialist.

Having said that, if you need a fuel filter for your lawn mower, e-commerce sites like Amazon offer some excellent discounts on a pack of fuel filters that fit a variety of popular brands.

Note: You should stop using a recalled Kawasaki engine if it leaks fuel and immediately get in touch with Kawasaki or a Kawasaki dealer for a free repair or replacement.

3. Engine Won’t Start

Another prevalent issue customers have highlighted is an engine that won’t start.

Imagine a day when you are prepared to perform landscaping work or mow your lawn. You pull out the mower and get ready to begin your task, but the mower’s engine won’t turn over. Wouldn’t that be annoying? YES, it would be.

So, here are some causes that may prevent the Kawasaki FX730V from starting in one go.

  • Loose spark plug
  • Worn out or damaged spark plug
  • Clogged carburetor
  • Faulty pistons, cylinders, or head gaskets
  • Faulty engine valves 
  • Defective ignition coil
  • Leaking gas or fuel
  • Dried out or missing carburetor gasket
  • A faulty battery that drains quickly 
  • Clogged air cleaner 
  • Water mixed in the fuel
  • Faulty fuel system
  • Incorrect fuel type


We can understand that stuttering or a failed engine is highly frustrating. But the good news is that if you can identify the underlying problems, you can quickly fix your mower engine without needing professional help.

Spark plug:→ Replace the spark plug
→ Tighten if you find the spark plug loose.
Carburetor:If the carburetor is clogged, try cleaning it with a carburetor cleaner.
→ If cleaning is not possible, replace the old carburetor with a new one
Coil:→ Change the fuel
→ Keep the fuel tank filled
→ Change the fuel filter or tube if necessary
→ Clean the fuel tank cap
Battery drainage:→ Check the voltage regulator. If you find any problem there, fix it.

Here are some fixes for a non-starting engine in addition to the ones listed above.

  • By removing the flywheel from the engine, you can check the flywheel key, a tiny metal component that slides into the crankshaft and interacts with the flywheel. If the flywheel key is damaged, replace it.
  • The engine may also be unable to start due to a defective recoil starter. Check it out and replace it if it doesn’t function properly.
  • Check to see if the safety switch is broken.
  • If the start switch is malfunctioning, replace it.

4. Battery Draining

What if your Kawasaki FX730V engine has a defective battery that frequently drains? It might present some serious problems, the most frequent of which are stuttering or a shutdown engine problem. So when you mow the lawn, be mindful of this problem.

The most frequent reasons for the Kawasaki FX730V engine’s battery drains are listed below.

  • Loose Battery Cables

The battery will struggle to run correctly if the battery cables are loose. In addition, you may experience loose battery cables due to the mower’s continuous vibration over time, which can cause the battery to work extra hard to provide power to the machine.

  • A Bad Or Faulty Alternator

Because the alternator assists the battery is running, it has to push hard to make up the void if it fails. It would also imply that the battery is not receiving enough charge to keep it in prime shape.

  • Bad Voltage Regulator

The voltage regulator’s primary job is to ensure that the battery receives the proper voltage from the alternator to maintain the battery charge.

A poor voltage regulator, however, won’t perform as intended and will stop the battery from receiving enough voltage. This is a significant factor contributing to constant battery drainage.

Signs of voltage regulation problems:

  • Stuttering engine
  • Dim lights of the mower
  • Jumping of the voltage level dial, etc.
  • Electronic Drainage

Occasionally, a small electrical charge remains active even after turning the lawn mower off. A constant active electric charge could over-drain the battery unnecessarily by always sapping its power. This is called parasitic electronic drainage.

  • Poor Maintenance Of The Battery

Another important reason the battery might keep losing power is poor maintenance. If all other components operate as intended, but the battery drains rapidly, you may not be maintaining the battery correctly.

Also Read: How to Change a Lawn Mower Battery: Simple and Easy Way!

  • Keeping The Ignition On When Not Using The Mower

If you are one of those who forget to switch off the battery of the mower when leaving it for a long time, you will undoubtedly face excessive battery drainage. Although it may look like a simple mistake, it can cause the life of your mower’s battery.


The FX730V engine battery can be over-drained with a few simple fixes. Please read the information below to learn simple solutions to the battery-draining problem.

Loose battery cables→ Wiggle the cables to check if they are loose.
→ Tighten the loose cables if required.
Bad or faulty alternator→ Check the alternator output by using a multimeter.
→ If the alternator is bad or failing, fix it.
Bad voltage regulatorCheck the voltage regulator by using a trusty multimeter.
→ A faulty voltage regulator will need to be replaced.
Electronic drainage→ If there is parasitic drainage of the battery, take the engine to an authorized service center to get it fixed.
Poor maintenance of the battery→ Check the dirt or corrosion of the battery terminals. Clean the battery terminals to maintain the battery’s longevity.
→ Fill the ports with distilled water to raise the liquid level if necessary.

Note: Before deciding whether the ports need to be filled with distilled water, please read the manual. Also, pay attention to where the liquid level needs to be filled. Never fill the ports to the brim.

5. Reduced Engine Speed or Runs Poorly

Customers of the Kawasaki FX730V have also frequently complained about the engine’s poor performance or low speed. Therefore, we had to include this problem in our list. Here are some typical reasons the FX730V frequently runs slower than expected.

Overheated engine → Debris buildup on radiator fins
→ Malfunctioning of the temperature sensor
Low oil pressure→ Low oil level
→ Malfunctioning lubrication system
Clogged carburetor→ Engine cranks but doesn’t start
→ Running lean
Damaged spark plug→ Slow acceleration
→ Loss of power
Malfunctioning of the throttle valve control→ Due to corrosion or humidity
→ Internal contamination
Malfunctioning of the hand throttle input sensor→ Difficulty handling
→ Lacks power
Clogged fuel filter→ Loud noises from the fuel pump
→ Stalling vehicle


The spark plug should be examined first. Replace it immediately if you find it to be damaged. The carburetor should be checked next.

An obstructed carburetor will make the engine run rough. Therefore, it is suggested that you clean it with a carburetor cleaner. You might need to consider replacing the entire carburetor if that is insufficient.

The cooling system must be cleaned if an overheated engine is a culprit. To cool the engine, you could also spend money on coolant.

Checking the fuel filter is the last but not the least step. Clean it if you find it to be clogged. However, if the issue is severe, you might need to switch out your old fuel filter for a new one.

Caution: Drain the old fuel from the fuel tank before changing the filter.

What Do Most Customers Feel About Kawasaki FX730V?

Kawasaki is a tycoon in the industry. Thanks to its reputation for producing motors that power some of the top tools and cars, this is a highly reliable brand. And this reputation of the brand is well upheld by the FX730V engine.

If we keep the issues of the FX730V aside, this engine is of professional grade. This engine, which is intended for homeowners, can easily handle a variety of landscape challenges.

It has a 23.5 horsepower forced air-cooled v-twin engine. A rotating grass screen and electronic spark ignition are additional features.

Therefore, if the brand’s claims are to be believed, the Kawasaki FX730V engine is of the highest caliber. However, it is crucial to read what actual customers have to say about this engine to double-check its efficacy.

Here are a few of the most noteworthy customer testimonials about the Kawasaki FX730V engine.

  • “5 stars for the engine as far as fit, performance, and ease of install having only 2 wires which control the carb plunger.”
  • “The engine is excellent….”
  • “Great!”


Is the Kawasaki FX engine series any good?

Yes, absolutely. Professional-grade engines with high power are available from Kawasaki under the FX series. 

The series consists of small, V-Twin  4-cycle vertical shaft engines with attributes like electronic spark ignition, heavy-duty shift-type starter, rotating metal grass screen, and forced air cooling. 

Between 13.2 and 31.4 horsepower are produced. Most riding mowers used for residential purposes can operate within this range.

What is the average lifespan of a Kawasaki engine?

Kawasaki excels in terms of construction quality.

How well you maintain and use your Kawasaki engine will determine how long it lasts, among other factors. 

To answer the question above, however, we cannot confirm any particular time. Nevertheless, a Kawasaki engine typically lasts between 100k and 200k miles, or 2000-3000 hours.

How can I keep my Kawasaki engine running at its best?

Maintaining the Kawasaki FX730V engine will help it run as efficiently as possible.

You can perform the following actions to ensure proper maintenance:

• Regular service of the air filter
• Check and service the oil filter
Check and replace the oil
Use the right oil
• Service the cooling system
• Keep the carburetor clean, etc.

Where can I buy a Kawasaki replacement engine?

You can easily buy a Kawasaki replacement engine from an allowed Kawasaki Engine dealer. To find a local dealer, click here.

The Bottomline

So, this was our take on the Kawasaki FX730V Problems With Solutions.

We sincerely hope you’ve found this post on Kawasaki FX730V Problems With Solutions handy and that it will help you identify and resolve the engine issue with your lawnmower.

When dealing with a defective engine, we can recognize how frustrating it can be. But one benefit of Kawasaki is that the company meticulously concentrates on creating durable engines.

But a device can always go wrong. Therefore, maintaining your armor of knowledge and skills is essential to conquer problems.

About Jennifer Igra

Growing up in Brooklyn, New York City known for it’s green gardens. Jennifer, a 30 year old gardener and green living fanatic started Igra World to share her gardening journey and increase gardening awareness among masses. Follow Igra World to improve your gardening skills.

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