Kawasaki Vulcan Problems: 6 Known Issues (Explained)

Don’t let the 649 cc engine fool you. The Vulcan S model from Kawasaki packs a considerable punch.

With a history dating back to the ’80s, the Kawasaki Vulcan models have undergone performance upgrades that make them a big player in the cruiser market.

Other than the Vulcan S, Kawasaki has great models in the Vulcan range. Vulcans are available from the Vulcan 900 Classic all the way to the 1700 Vulcan Classic Voyager.

Kawasaki has made sure to make a mark in the motorcycling industry because these are genuinely great bikes.

Looking at the Vulcan can sometimes seem like these are unstoppable bikes, and nothing can go wrong. Unfortunately, this isn’t the case.

We’ve done some digging and found common issues with the Kawasaki Vulcan Models.

In this article, we’ll be going through some of the problems experienced by these bikes.

Let’s get into it!

1. Oil Pump Failure

This problem was particularly prevalent in the Vulcans manufactured in the late 90s/ early 2000s.

Although it can be solved by a simple replacement of the oil pump, it’s still a problem worth mentioning, especially for any of our reader’s window shopping a used Vulcan from the aforementioned era.

The issues that result from a failing oil gear pump will usually show up between 4,000 miles and 15,000 miles on the bike. If you’re in the market for a used Vulcan, be sure to inquire about the condition of its oil pump, any problematic history the pump has, and whether it’s been upgraded.

Again, these are great bikes; with an upgraded oil pump a used Vulcan is a score.

Just in case you already bought your Kawk and are wondering if you’ve got a bad pump on your hands, here’s what to look out for:

Symptoms of a Failing Oil Pump Include:

  • Tapping noises from the engine
  • Check engine oil light coming on
  • Intermittent starting
  • Loud Whining sound from the clutch cover area
  • High oil pressure

Keep in mind that the oil pump problems mostly affected older variations of the Vulcan.

This includes models from 1999 through 2005. This was due to Kawasaki having used plastic components in the pump instead of metal, an oversight the Japanese brand has since rectified.

These plastic pumps were weak, and many Vulcans faced the issue of having to replace them. The problem was solved by Kawasaki replacing the pumps under warranty.

These days, there are only a few Vulcan models that experience this problem. This is because Kawasaki went and upgraded the oil pump from plastic to metal.

The problem was most common on the Vulcan 1500 Classic models, and owners opted to replace the oil pump with a third-party one.

Replacing the oil gear pump seems to solve the symptoms listed above.

2. Regulator/Rectifier Wears Early

While some riders say the Regulator/Rectifiers on Kawasaki Vulcans burn out early, others say it results from poor storage or upkeep on the older models.  

Moto-maniacs debate the cause of the Vulcan R/R’s early death.

Some say it’s the fact that the Vulcans all used sealed, liquid-cooled engines. While the machine is flushed with coolant, nothing cools the Regulator/Rectifier which is then trapped in the sealed motor.

In the 90s, and early 2000s, it was typical for the R/Rs on liquid-cooled V-twins of all makes and models to burn out early, as it took engineers a while to design parts that could withstand the internal heat of a sealed engine. 

It hasn’t been a common problem in the last decade; since those old Vulcans run forever, we figured we’d put it on your map.

What Is a Regulator/Rectifier?

Like most bikes, the Vulcan uses batteries that replenish via electric systems.

That system generally includes a part called the Regulator/Rectifier (R/R), which regulates and rectifies voltage by converting AC into DC and fixing the DC power under 14.5 volts before routing it to charge the battery.

To be clear, like any engine part, all Regulator/Rectifiers fail someday. The criticism here is that an old Vulcan’s R/R dies earlier than it should. 

How to Know If My Vulcan’s Regulator/Rectifier Is Failing? 

There are two direct ways that the regulator/rectifier can fail. 1. Diode burnout, which prevents the battery from charging and exhibits the following symptoms:

  • Inadequate starts,
  • Inconsistent voltmeter readings,
  • Dimming or flickering headlights.

2. A Shunt regulator burnout results in the R/R failing to rectify the voltage levels. This puts an overcharge on the battery and, in severe circumstances, can even cause the battery to blow up. 

Symptoms of a shunt regulator burnout are:

  • The battery charge reads above 17 volts, suggesting that the regulator/rectifier failed to convert the surplus power. 
  • Your Vulcan’s headlight increases in illumination and then blows out.
  • The Vulcan’s wiring harness is in visibly poor condition. 

How to Test Your Vulcan’s Regulator/Rectifier for Failure 

Follow these steps to inspect the virtue of your Vulcan’s regulator/rectifier:

  1. To test the Rectifier, disconnect the wires in your Vulcan and set the multimeter to the diode operation.
  2. Check the positive diode by connecting the positive lead to the Vulcan’s positive diode.
  3. Secure your negative lead to the stator. Your meter shouldn’t read anything.
  4. Attach the positive diode to the stator’s negative lead.
  5. Attach the positive to all stator inputs. The meter should give you a reading; any reading is fine as long as it’s picking up something. 
  6. Attach the positive lead to the negative diode and secure the stator inputs and negative lead.
  7. The meter shouldn’t read at all.
  • To check the regulator, connect the meter leads to your Vulcan’s battery while your Vulcan is idling. Your reading should be less than 13.5 volts. If it’s higher, your Vulcan’s battery is overcharged, and your R/R could be faulty.

How Do You Fix a Failing Regulator/Rectifier on a Kawasaki Vulcan?

The only way to fix a failing Regulator/Rectifier is to replace it with a new R/R; Regulator/Rectifiers for your Vulcan are relatively inexpensive, and it’s a quick job for a decent mechanic. 

As far as the older Vulcans go, an aftermarket R/R might handle heat better than the stock piece. Some of the R/R’s Kawasaki made, later on, might work; you’ll have to research to find an upgrade that fits your particular make and year model Kawasaki Vulcan.

3. Noisey Drive Pulley

This is another issue that got nipped in the bud circa 2008; fortunately, this list item isn’t so much of a common problem as it is a frequent complaint.

Still, we figure we’d better cover it, as it seems to be a FAQ in many of the Vulcan forums.

The drive pulley is the component responsible for driving the primary belt. According to the slue of complaints online, the Vulcan’s drive pully makes more noise than is standard on motorcycles. 

My assumption is that it has to do with the big ol’ Harley-Davidson-style Primary belt, as certain HD models garner the same complaints.

The Vulcan is certainly an homage to American cruisers–it’s no accident that it stocked a fat belt-driven primary like the HD’s.  Regularly lubricating the teeth with oil has been known to dampen the sound in some cases, while in others riders just learn to live with the noisy primary, appreciating its rattle as a characteristic of a powerful, beefy cruiser.

For those of you who are here because your drive pully or primary belt are making new, unconventional sounds, we’ll go into a few potential problems that it could be.

To be clear, these aren’t indicative of specific problems with the Vulcan, just a few general places to start troubleshooting on any belt-driven primary that’s clanking around.

Problems Indicating a Failing Drive Pulley:

  • Belt Teeth Need Oil
  • Belt Tension Too Loose or Too Tight
  • Drive Pulley Nut Coming Loose
  • Belt Alignment is Not Accurate

Problems with the drive pulley will usually show themselves as noises coming from the belt.

It sounds like the belt is rubbing up against something and producing a squealing noise.

In many of the cases reported in the forums, riders say the noise was exaggerated after the bike had fallen or had gotten into an accident, or after they replaced the belt.

The belt tension on the Kawasaki Vulcans is very sensitive–overtightening the belt incorrectly will usually result in a noisy belt or faulty drive pulley system. A primary belt that’s too loose will also cause issues with the Vulcan’s belt and drive pulley system.

Most problems that arise with a noisy belt usually indicated an incorrectly adjusted belt tension.

Swapping out the belt for a new one can work, but the tension must be just right when installing the new drive belt. So it is recommended to have a mechanic or dealership deal with the installation.

Having visited a mechanic, other owners found out that the nut on the drive pulley had come loose.

The nut coming loose is not as common as the belt issue but affects many riders. A loose nut can result in some wear and tear on both the drive pulley and the output spline shaft.

NOTE: At the end of the day, inspecting and maintaining your gearbox will ensure your drive nuts stay tight and your primary belt stays in adjustment. Transmission inspections are routine on any vehicle and are part of the service schedule outlined by Kawasaki in the Vulcan’s manual.

General Pros and Cons for the Kawasaki Vulcan Models


The Kawasaki Vulcan models were a big player in the cruiser market, especially in the US.

This might be because of the great handling and the power of the engine.

The Kawasaki Vulcan S model has a steady crop of Kawasaki cruiser fans. It puts out a maximum of 6600 RPM at 63Nm, and all that power comes to a smooth stop with an improved braking system.

Most owners of the new Vulcan S model from Kawasaki brag about its stopping power. The bike features ABS and a single 300mm disc front brake.

You should also be reading our article which talks about 6 Most-Common Problems With Kawasaki Versys 650

The Kawasaki Vulcan models’ seating position has always been comfortable and can go up against some of the best cruisers in the same range.


  • Oil Gear Failure Issue
  • Stator And Regulator/Rectifier Issues
  • Drive Pulley Problems
  • Vulcan Engine Whine Noise Issue
  • Output Shaft And Bevel Gear Failure
  • Vulcan 800 Speedometer problems

What Do the Reviews Say?

“Little creature comforts, such as a clever neutral-finder at stops, floorboards, and a backrest for the passenger, plus electronic cruise control, add to the superb package that makes the Kawasaki Vulcan 1700 Nomad a great model you might not have considered.”

[Source: UltimateMotorcycling.com]

“Kawasaki market research has determined that a primary concern for motorcycle buyers—first-timers and experienced riders—is finding a motorcycle that physically fits. Picking a new bike is not unlike trying on a new pair of shoes, and it is here that the all-new Kawasaki Vulcan S Ergo-Fit concept provides a fresh approach.”

[Source: CycleWorld.com]

What’s The Resale Value On The Kawasaki Vulcan Models

Model Year Mileage (miles) Price ($)
Vulcan 1600 Classic 2005 26,119 3,200
Vulcan 900 2008 23,352 2,600
Vulcan Vaquero 1700 2012 31,993 6,990
Vulcan 900 Classic 2016 4,733 5,295
Vulcan S ABS 2018 5,681 4,999
Vulcan Vaquero 1700 ABS 2019 15 16,795
Vulcan 1700 Voyager ABS  2019 28 14,999

NB: These prices are estimated and may vary concerning your location. Also, the model and the mileage may play a part in its price range.




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ⓘ  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.