Kawasaki Engine Problems: Diagnoses, Fixes, And Tips

It’s almost impossible to have a serious conversation about small engines without talking about Kawasaki and their unrivaled track record. The Japanese brand is a titan due to its reputation for producing motors that power some of the finest power tools and vehicles money can buy.

Like with most all mower, Kawasaki engine problems do exist. Though they make a quality product there can be problems with the crankshaft upper seal, ignition coil, anti-tilt switch, fuel filter, and even issues with engine surging. The fixes range from the simple to complete engine replacement.

Unfortunately, even Kawasaki engines are not infallible. As they can be vulnerable to a wide range of problems over time. In today’s article, we will discuss these problems, their causes, and any possible solutions. Let’s get started!


What Problems Do Some Kawasaki Engines Have?

Though Kawasaki is an elite in the world of lawn mower and tractor engines, no machine or manufacturer will be completely without faults and errors. Here we will discuss some of the common problems that owners face with this popular engine.

And to be clear, this engine shows up in many brands of mowers even if the Kawasaki logo is not prominently displayed.

Upper Crankshaft Seal Leak

In order to change the energy supplied by the vertical motion of the pistons in to circular motion for the flywheel and fan belt a crankshaft is needed to bridge this divide. It acts as a relay between the systems of an engine to keep the flow of kinetic energy going.

These moving parts naturally cause friction as one piece rubs against the other at high rates of speed. This requires lubrications. Oil is the main way this is achieved.

The Problem:

The problem occurs when there is a leaky seal in the upper portion of the crankshaft. The oil that was meant for lubrication and to cool down the moving parts of the engine leaks out and becomes cakes on the fins in the head area and can overheat the engine.

This area also will collect dust and grass clippings further insulating and raising heat levels. Eventually this can cause complete engine failure due to heat and the ‘ceasing’ of some moving parts.

The Solution:

Remove the top cover and inspect the engine for oily or caked areas, especially around the fins and heads. These areas if found dirty should be cleaned and free of debris.

This should allow your engine to run for many more years as long as this regular maintenance is performed once to twice per cutting season. This simple fix can save you from having to replace the motor or buy an entire new mower.

Bad Coils

The starter coil as it is sometimes knows is responsible for transferring electricity between the battery where it is stored to the sparkplug where it is used to power the engine itself. The part itself is relatively inexpensive at $15 – $25 but is vital for the running of your mower.

The Problem:

If this part becomes faulty, it can prohibit the engine from starting or could cause uneven idle and stalls.

The Solution:

The main way to fix a bad coil is to replace it. It can be done by the experienced DIYer or landscaping professional. Yet, for those not sure on how this is done, a professional small engine specialist is your best bet.

Here are some coils for some major brands found on Amazon…

There are many types and with each one you will need to check the horsepower and other specs to ensure you are getting the proper parts.

Faulty Anti-Tilt switch

Some models of Kawasaki motors are equipped with anit-tilt switches on the motor itself. These are to ensure that the mower does not continue running if the engine is angled to a dangerous degree that could result in tipping. It is essentially a kill switch that deploys once a maximum allowable tilt is reached.

The Problem:

If these sensors, sometime electrically based and sometimes filled with mercury, go bad the engine could cease to operate at random times. This could also cause the engine to not function at even the slightest of inclines.

The Solution:

It is possible to check this switch by disconnecting its ground wire temporarily to see if the engine runs normally without it. This should only be done for testing purposes and should not be done as a permanent solution.

For a permanent fix once the problem has been diagnosed, a new switch should be installed. This can be done by some mower owners comfortable with small repairs on their mowers, but for those unfamiliar with mower electrical systems, a small engine expert should be sought.

Fuel Filter Leak

The fuel filter is responsible for straining all gas before it enters the mower’s carburetor to ensure no contaminants enter the firing chambers. If foreign contaminants were allowed to enter your engine, they could cause a host of problems.

The Problem:

Around 2013 there was a recall on all Kawasaki mowers due to faulty fuel filters. These filters were known to leak oil onto the engine posing a fire hazard. The recall effected many of the major brands that used Kawasaki engines.

  • Gravely
  • Bad Boy
  • Bob-Cat
  • Cub Cadet
  • Exmark
  • Ferris/Snapper
  • Husqvarna
  • Hustler
  • SCAG
  • Toro

Not only was this a problem then, but this can be an issue with most any filter and mower engine. These inexpensive mass produced parts can have defects during production. They can also become damaged with use.

The Solution:

The number one way to fix this problem is to replace or have the fuel filter replaced. Again, for those comfortable with DIY fixes on their mowers, this can be a simple process. For those not comfortable with the self install option, seek out a qualified small engine specialist.

To get a great deal on a pack of these fuel filters that fit many major brands, I recommend this 10 pack from Amazon…

Gas Inline Fuel Filters with magnet for Kawasaki Kohler Briggs & Stratton John Deere

Finally we should talk about engine sure in the Kawasaki line. Though there are some instances worse than others, it can be a pain to remedy. To be fair, most all engine brands can have this problem. Kawasaki is no exception.

To see some other great articles from LawncareGrandpa.com…

What Causes A Kawasaki Engine To Surge?

Every once in a while, you might bring out your lawnmower for a bit of trimming only to find it fluctuating between high revs and low revs without any input from you.

When a Kawasaki engine revving fluctuates, this is known as “surging” and it is a direct result of inconsistent volumes of fuel and air being delivered to the engine’s combustion chamber. The problem will lie with the fuel filter, injectors, lines, or the carburetor.

Remember, combustion requires both fuel and oxygen.

Typically, greater volumes of fuel/air will lead to bigger combustions and higher engine output. Reduced fuel/air quantities will lead to lethargic idling and diminished revs. 

This problem almost always stems from the fuel delivery system (fuel injectors, fuel lines, or the carburetor) or air intake channels.

As such, if you notice surges, you should:

  • Inspect the carburetor and fuel lines
  • Inspect, clean, or replace the air filter
  • Drain aged fuel from the fuel tank
  • Inspect fuel-air inlet valves for leaks

How Long Does A Kawasaki Engine Last?

Kawasaki Engines, operating as a subsidiary of Kawasaki Heavy Industries, has been in the small engine game for almost half a century. 

This kind of longevity is only possible if you make and market high-quality products for broad markets, which Kawasaki does. The small engine subsidiary has established a presence in most of the globe’s major markets.

The popularity of Kawasaki engines is fueled by several different factors including power output, fuel economy, environmental friendliness, and their versatility.

However, Kawasaki truly shines in the build-quality department, which results in engines with notoriously long lifespans. Depending on the frequency of use and maintenance, a Kawasaki motor’s life can span 10 years or more. Kawasaki motors are famous for hardly ever needing “out of the ordinary” repairs and fixes. 

In warranty terms, Kawasaki often puts 3-year warranties on its 4-cycle engines. That translates to about 3,500 hours of runtime with 50-hour mark service intervals.

We highly recommend timely service and routine inspection of your motor, especially after long periods of storage. Tools and vehicles powered by Kawasaki engines are often accompanied by service schedule charts that detail the services to be done as well as the intervals at which they will be done. You can also find oil guides to help you identify the best oil for your motor.

Storage can also have an impact on engine longevity. Make sure the tool or vehicle is stored away in a cool dry place away from the elements. You can also use a tarp to protect against dust.

Are Kawasaki FR Engines Any Good?

Let’s look at one of the more popular Kawasaki engines that seem to have much less in the way of problems when compared to other engines even within their own offerings.

Lawncare is a big chore that should be done using big tools. Power mowers, lawn tractors, and z-turns are the obvious go-to solutions, and they all need reliable power sources.

True to form, Kawasaki hasn’t shied away from the challenge and has produced multiple ranges of commercial and residential lawnmower engines over the years.

One particularly eye-catching range on offer these days is the FR series, which has slowly become something of a standard-bearer for residential mower motors.

The series is made up of compact V-Twin engines geared towards high power output and minimal noise. The FR series has been widely touted as a true contender to Briggs & Stratton’s V-Twin crown.

Various lawnmower manufacturers use engines from this series for their riding mowers, and for good reason. The 4-cycle motors are perfect for working any yard and they can also put in a decent shift for smaller commercial jobs.

FR series engines feature cast-iron cylinders that are highly resistant to long-term corrosion. They also boast forced air cooling, a feature that always proves its worth during brutally hot summer months.

Kawasaki has always had a penchant for big surprises in small packages, and the FR line is further evidence of it. The engines are all fairly lightweight given the level of performance they can dish out. Engines in the series range from about 80-90lbs, which is quite impressive.

Power output levels range from 18 horsepower to 24 horsepower. This is the perfect range for most residential use riding mowers.

Now, let’s take brief looks at each of the four engine models in the series.

The FR600V Kawasaki Engine

First up is the entry-level FR600V, an 18 horsepower OHV motor with 600ccs of pure lawn-trimming power. The engine peaks at about 3,600RPM while the maximum torque of 43.7 Nm is reached at 2,200RPM.

The FR600V certainly sets the tone for the rest of the series with features like an internally vented carburetor, a rotating glass screen, and (of course) the 90-degree V-Twin cylinder layout. This baby also comes with electronic spark ignition.

The FR651V Kawasaki Engine

Next, we have the FR651V, which leans a bit more to the commercial side than the FR600V. 

You have a bit more displacement (726cc) and power output (21.5 horsepower). The torque is also higher at 53.2 Nm. The engine itself weighs just over 88 lbs. 

The rest of the FR651V’s features are shared with the FR600V.

The FR691V Kawasaki Engine

The third FR engine is the 23 horsepower FR691V. This is arguably Kawasaki’s sweet spot offering as far as the residential-commercial balance goes.

The motor weighs in at 88.2 lbs and has 726ccs of displacement. Torque and max power RPM figures are the same as the FR651V.

One FR691V feature that you don’t get on the first two models is a fuel shut-off solenoid on the carburetor.

The FR730V Kawasaki Engine

Finally, we have the jewel in the FR series’ crown, the FR730V

This 24-horsepower motor is an awesome choice for both private residences and commercial jobs as it combines everything great about the other engines in a slightly more powerful package.

You get the same displacement and RPM values as the FR691, although maximum torque is slightly higher at 53.9 Nm. The engine also weighs in at 88.2 lbs. Most other standard features are shared with the FR691.

So, in a nutshell, FR series engines are definitely good motors and they are more than worth it, especially if you are in an area with very high temperatures. Their relatively low noise and emission levels are also unlikely to fall foul of any homeowner’s association rules.

This quality construction and attention to detail also keeps down some of the problems of older Kawasaki engine lines.

The Final Touches On Kawasaki Engine Problems…

Hopefully you have found this information about Kawasaki engines helpful and it can lead to you finding and fixing the problem with your mower’s engine. It can be frustrating when problems arise, but Kawasaki engines are quality products and usually the things that do go wrong are simple parts and fixes.

To see more on mower engines, see my articles here…




Mathew Booe

Mathew has worked in landscaping professionally for over 10 years. He is a grandpa and frequently interviews other experienced landscapers and lawn care experts who are also grandpas for these articles.

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