Kawasaki W800 Problems: 4 Known Issues (Explained)

The Kawasaki W800 is one of the most sought-after cafe racers on the moto-market.

Cafe Racers, or modern classics,  have grown in popularity in recent years. With their vintage aesthetics and straightforward riding manners, they are attractive options for urban dwellers.

If modern classic motorcycles are your thing, the Kawasaki W800 is an excellent choice. However, W800 owners have experienced a few complications over the years, and we’ll outline their troubleshooting in this article.

Based on our research, here are the most widespread predicaments associated with Kawasaki W800 bikes:

1. Cracked Intake Manifold Assembly

Numerous customer complaints have led to the classification of cracks in the intake manifold assembly not just as a common problem for Kawasaki W800s but as a defect that resulted in a recall.

According to reports from both owners and the manufacturer, the issue lies in the intake manifold system’s throttle body holder.

According to numerous sources, the engine’s heat leads the throttle body holder to abnormally rapid deterioration.

Repeated exposure to periods of heat (from the engine) hardens the throttle body holder. Once hardened, vibration makes the part susceptible to cracking. A crack in the manifold allows air to leak into the engine.

Naturally, leaks increase the air in the engine and can cause several problems. The more air you have in the motor, the ‘leaner’ the air-fuel ratio.

Lean air-fuel mixtures can raise engine temperature and cause it to run rough. As an air-cooled bike, the W800 is more susceptible to overheating.

We’ve curated a list of common symptoms of a cracked throttle body holder on the W800:

  1. High idle: The bike’s engine revs too fast or shakes excessively when the bike is idling.
  2. Unstable engine speed:  Unusually high air intake can make the W800’s speed fluctuates while riding.
  3. The engine takes longer to settle down: Normally, if you close the throttle, the engine’s RPM should fall. The lean fuel mix affects that throttle-down response.

Possible Solution

Kawasaki issued a recall for the affected bikes, upgrading the faulty throttle body holders to an updated stronger designed part.

Kawasaki estimated that 5,973 motorcycles fell under the recall, but there’s that they didn’t all make it in for the swap out.

If you discover a crack in your W800 intake manifold assembly, take it to your local Kawasaki dealership; there’s a good chance your bike is dues for an upgrade, and, hopefully, it’s on the house.

2. Multiple Electrical Problems

Here’s another small piece of recall history for Kawasaki; this time, the recall pertained to electrical issues on, not all but some W800s released between 2011 and 2016.

This time, the issue was a faulty electrical wiring harness.

The harness may have been installed inadequately on the motorcycles in question, making it damage-prone, especially below the fuel tank.

Harnessed on affected bikes became caught between the tank and the frame.

Friction on the wires can rub the coating off in time.

If exposed, the wires could contact the bike’s frame, causing a short circuit that could impair engine-function or even stall the bike out altogether.

Possible Solution

Kawasaki recalled all bikes with VINs between JKBEJ800AAA015861 and JKBEJ800AAA026549 and mandated dealerships to upgrade the wiring harness for free.

Also, mechanics were prompted to add a new protective covering and to re-route the updated harness.

If your bike’s VIN falls between these numbers and you’re unaware of whether or not the harness has been updated, have no fear; a Kawasaki dealership can pull your VIN and let you know if your harness needs an upgrade.

If you’re due, they’ll knock it out at no cost.

3. Bike Hesitates While Accelerating

Throttle response is a crucial element to the art of operating a motorcycle.

As a rider, you expect your input on the throttle to affect your acceleration as immediately as possible.

If acceleration lags or becomes erratic, then something is wrong.

We’ve encountered a few Kawasaki W800 owners who have reported their bikes stuttering on acceleration. The engine acts like it’s about to die, then it catches and speeds up as normal. 

Likely causes for this problem include:

  1. Dirty spark plug: Buildup of carbon and oil residues on spark plugs and pitting will lead to a weak spark. This will eventually result in poor acceleration and ignition.
  2. Clogged air filter: A clogged air filter affects throttle response by preventing the combustion chamber from getting enough air. If this happens, the fuel mixture will be rich, causing poor acceleration.
  3. Faulty throttle position sensor: The throttle position sensor feeds the rider’s throttle input to the bike’s computer and regulates the air-fuel ratio accordingly. If it’s faulty, the information your CPU receives will be inaccurate, and the skewed ratio will tamper with the bike’s acceleration.
  4. Cracked manifolds: A cracked manifold will cause air to leak into the combustion chamber, creating a lean fuel mixture. A lean fuel mixture often causes a motorcycle to hesitate while accelerating.

Possible Solutions:

  • Replace dirty spark plugs
  • Replace the air filter if it’s clogged/dirty
  • If it’s the throttle position sensor (TPS), take it to a technician for repair. You may need to replace it if it’s severely damaged.
  • Seal the cracks in the intake manifold or get a new intake manifold

NOTE: Review Section 1 to determine if your bike is due for a recall, especially if you’re having issues with your intake manifold assembly.

4. Repeated Exhaust Backfire

Some W800 owners have reported experiencing exhaust backfires on their bikes.

A backfire is a loud popping or banging noise that comes out of a motorcycle’s exhaust while it’s in operation.

While it won’t affect rideability, backfiring could affect your hearing, especially if you’re in a confined area. In a worst-case scenario, the exhaust pipes could emit flames.

You should also be reading our article which talks about 4 Most-Common Problems With Kawasaki Brute Force 750

Backfiring generally occurs during the deceleration of the motorcycle.

That said, it’s not unheard of for a backfire to pop off while starting or accelerating either.

Possible causes of backfiring  include:

Rich/Lean Engine:

If your engine is running either rich (excessive fuel) or lean (excessive air), chances are you will experience exhaust backfire.


Both cases often cause incomplete combustion of fuel, allowing heat from the exhaust to ignite the fuel mixture out-of-turn. 

This faulty ignition eventually leads to the popping sound you hear when the bike backfires.

Exhaust Upgrades:

Most W800s we’ve encountered that suffer frequent backfires have had their stock exhaust systems ‘upgraded’ with an aftermarket variant.

Each set of pipes needs to be tuned to the rest of the motor to maintain an air-fuel ratio ideal for the specific motor. Whether you’re changing the pipes or the air intake, a retune is required.

Other culprits for a backfire include:

  • clogged air filters
  • faulty fuel pumps,
  • poor fuel grade

Notice that all the causes have significant effects on the air-fuel ratio.  This is intentionally balanced ratio needs to be maintained, and even a slight increase or decrease in air or fuel at the hands of new, clogged, or faulty parts can alter it.

Pros of Kawasaki W800

Here are some pros of the Kawasaki W800:

1. Comfortable to Ride

The W800 has a flat seat and upright hand-bars, two things that give it relaxed riding manners. Moreover, it has a well-designed suspension and is comfortable to ride over long distances.

If comfort is a major consideration for you, buy the Street variant. The W800 Cafe is sportier and features a more aggressive, albeit uncomfortable, rider stance.

2. Classic Styling and Design

Almost everyone agrees on one fact about the W800: its retro design is simply amazing.

Based on the 60s-era Kawasaki W1, the W800 has a vintage styling that is sure to turn heads.

If you like that classic-bike look and feel, the W800 is perfect for you.

3. Good Fuel Economy

The W800 is a low-revving sub-800cc bike with a maximum output of 46 pound-feet of torque.

Given these specs, it is no surprise that the W800 gets great gas mileage.

From reports, this bike gets between 55 to 60 MPG. For those who want a fuel-efficient city-friendly bike, the W800 is a great option.

4. Innovative Seat Design

Did we say the W800 is comfortable to ride?

Well, here’s another reason to believe us. The W800 features an elongated, comfortable seat with thick padding and has plenty of room for both rider and passenger.

On similar bikes, the piping around the seat’s edge often cuts into the rider’s thighs.

The piping on the W800’s seat follows the line between the rider and the passenger’s legs to prevent this.

This ensures that it doesn’t cut into the rider’s thighs when the bike is stopped.

5. Modern Technology

The W800 may look like a vintage bike, but it packs features found on modern high-end motorcycles.

It has a multi-function Liquid Crystal Display (LCD) screen that features an odometer, trip meter, and a clock.

Other indicators on the instrument panel include:

  1. Fuel-Injection warning lamp
  2. Low fuel level indicator
  3. High beam indicator
  4. Neutral gear indicator and
  5. Oil pressure warning lamp

Cons of Kawasaki W800

Here are some disadvantages of the W800:

  1. Parts of the intake manifold may crack.
  2. Intermittent engine backfires
  3. Engine hesitates while accelerating.
  4. Widespread electrical problems

What Do the Reviews Say?

“The Kawasaki W800’s handling compliments that perfectly. Its old school, upright riding position, cute, slim proportions, and wide-ish bars blend seamlessly with the responsive but soft delivery to make the W800 ridiculously easy to get on and ride.”

[Source: Motorcyclenews.com]

“Thanks to the upright bars and flat seat, the Kawasaki W800 earns its chops as the consummate city motorcycle. The ergonomics and comfort establish the W800 as an ideal motorcycle for tooling around town, enjoying the attention of vintage-styling without the hassles of a 55-year-old machine.”

[Source: Ultimatemotorcycling.com]

What’s The Resale Value On Kawasaki W800?

Year Mileage Price
2019 3,548 $5,999
2019 1,224 $8,999
2019 4,492 $6,995

Final Thoughts

While the W800 has a classic design, it has all the comfort and quality of modern bikes.

If you want a bike that makes riding less stressful, go for the W800.

However, make sure you look for the problems we have listed in this article, particularly if you are buying used.

You can also use some of the solutions listed here to fix the issues on your W800 bike.

Was this article helpful? Like Dislike

Click to share...

Did you find wrong information or was something missing?
We would love to hear your thoughts! (PS: We read ALL feedback)

ⓘ  The information in this article is based on data from National Highway Traffic Safety Administration (NHTSA) recall reports, consumer complaints submitted to the NHTSA, reliability ratings from J.D. Power, auto review and rating sites such as Edmunds, specialist forums, etc. We analyzed this data to provide insights into the best and worst years for these vehicle models.