9 Common Kawasaki Ninja 650 Problems (Solutions Guide) - Engine Monitoring (2023)

The Kawasaki Ninja 650 is one of the most recognizable sports bikes in the world thanks to its iconic green design.

Ideal for city driving and technical cornering, this versatile mid-size machine features a 650cc parallel-twin engine.

However, like any bike, it is prone to problems.

In this article, we will go through some common problems and how to solve them.

1. Kawasaki Ninja 650 Ohne Arranca

Dead battery

If your Ninja's battery dies, your bike will click to start, but it won't spin.

• The battery powers all of your bike's electrical components, including the ignition, starting, and fuel injection systems.
• In some cases, the battery will not start the starter motor due to a low charge. The clicking noise your bike makes is due to the battery having enough energy to turn off the starter but not enough to move the coil to start it.
• You can test your battery at any auto parts store to determine if the charge capacity is still intact or if the battery has expired and needs to be replaced.
• If the battery is in good condition, it only needs a trickle charge for a while.
• In other cases, if the battery is toasted, you will need to replace it.

defective starter

If one of the main components of the starter fails, your Ninja 650 will click to start but will not start.

1. The starter relay is the component that transfers charge from the battery to the starting system.
2. The solenoid is the starter's electromagnet generator that activates your Ninja's starter once it has been charged by the relay.
3. Once activated, the starter sets the engine's flywheel in motion, initiating the Ninjas piston process to bring your bike back to life.

When the battery dies the starter will click to start as there is enough charge left to activate the relay but not to magnetise the starter.

Once you've tested your Ninja's battery and are confident it's charged, the next best culprit is your starter motor.

The errors are of a similar nature and are therefore often confused.

The difference is that the clicking sound in this scenario is the starter gears not turning the flywheel; It is caused by failed magnetization, either from a bad magnet or a bad starter.

On the other hand, if you have a bad starter relay, you won't hear a click if your Ninja won't start.

This is because the starter solenoid doesn't get the juice it needs to click if its relay isn't working properly.

Gasoline pump Affairs

In other cases, like the cyclist below, the problem is related to the fuel filter, the pump, or a fuel pressure issue.

“I have a 2011 Ninja […] I have consistently had issues with the bike stalling and hesitating once it hits 6,000-8,000rpm, even sooner if I hit 100% throttle at lower revs. I have replaced the pump 3 times and the gills in the fuel pump housing once and it works fine for the first ride with all 3 pumps but when I drive again the same problem has returned and no way. I bought three new defective fuel pumps. I cleaned the injectors and fuel rail, still nothing.”

overfilled petrol tank

Overfilling the fuel tank on Ninja 650s with canisters can saturate the canisters with fuel and clog the fuel vent sufficiently to prevent air from entering the fuel tank. If the vacuum is too strong your Ninja 650 will not start unless you open the tank.

Here is an example of such a situation, straight from a Ninja Rider:

„My 2013 Ninja 650 sometimes dies and won't restart. In my case, it's because I always fill the gas tank to the brim before I go home and park my bike). The manual says not to fill the tank past the filler neck, but my gauge doesn't read quite as full when I do."

However, only certain bikes (California model) have carbon canisters.

Other problems could be a kinked fuel line (sometimes happens if you're not careful when reinstalling the fuel tank) or a faulty fuel pump.

2. Kawasaki Ninja 650 will stop working

Search the Ninja 650 forums and you'll find more than a few complaints from owners claiming their Kawasaki street bikes will start but won't keep running.

This particular problem seems to be more common among owners of 2007-2010 Ninjas, many of whom are for sale in the used car market.

Here is an example of a driver whose Ninja 650 starts but dies:

"II have a 2006 Ninja 650R that I bought last year. It worked well most of the year. Towards the end of the season it rained heavily so the bike sat outside untouched for about a month. At that time it would not work, but would shoot. When I press the gas pedal it stops and turns off. If I don't touch the gas it will work for 15-20 seconds and then die. The oil was emulsified but not foamy and there is no evidence of refrigerant in the oil (it is not foamy, just looks milky). I have washed and changed the oil, cleaned the air filter and will replace the fuel left in the tank [but the problem remains]".

More than a few Ninja drivers have experienced the same symptoms, which happen to be caused by water getting into the gas tank.

• There is a rubber hose in the fuel cap of your Ninja 650 that is used to remove water from the cap before it can enter the fuel tank.
• In some situations, the rubber hose is accidentally closed during maintenance.
• Once the hose is pinched or kinked, it prevents water from draining properly, causing it to pool in the lid gap.
• Once the water level reaches a certain point, it can flow into your ninja's gas tank.
• If a bent gas cap drain hose is the reason your Kawasaki Ninja 650 will not keep running, you will likely notice water collecting around your gas cap.

While this issue isn't exactly widespread, drivers can take a long time to diagnose it.

In scenarios like the Kawasaki rider mentioned above, it's a relief to find that the issue causing your Ninja to stop working after launch is so easy to fix:

“My friend was 100% correct [the problem was a pinched gas cap drain hose]. After taking the tank out, emptying it and putting in apple injector cleaner and dry gas it now runs and runs fine and idles. I did a 2x oil change and let it run for about 30 minutes; there was no smoke from the exhaust, so there were no problems with the head; the oil is now 95% clear.”

Related:How long do Kawasaki Ninja 650 last? (9 Important Facts)

3. Kawasaki Ninja 650 Ohne Arranca

If your Kawasaki Ninja 650 won't even try to start, check the battery first, then the starter relay. If these two parts are working properly, make sure your bike is neutral and the sidestand sensor is undamaged and free of dirt and grime.

This safety mechanism prevents you from accidentally riding the bike with the side stand down.

If the Ninja 650's jiffy stand switch is obstructed by potholes or dirt, the electrical signal will shut off. So the ECU assumes the stand is down, even if this doesn't cause the Kawasaki Ninja 650's engine to not start.

If the kickstand switch is defective or your Ninja 650 is running with the kickstand down, it will not start.

4. Kawasaki Ninja 650 will not start when hot

If your Ninja 650 runs fine when cold but stalls when hot, there could be a problem with the bike's cooling system.

Several Kawasaki owners have attributed their starting problems to engine overheating, often due to a radiator fan failure.

• The Kawasaki Ninja 650 is a liquid-cooled engine that uses a radiator, fan and cooling system to keep the engine cool.
• Unlike the open motor design of air-cooled bikes, the liquid-cooled Ninja motor is sealed and pumped with coolant.
• Due to its sealed design, the engine will quickly overheat if the cooling system fails for any reason.

In some situations, the Ninja 650's radiator fan will fail prematurely, significantly reducing the radiator's ability to pump coolant. The result is an overheated ninja engine that won't start.

Don't take our word for it; Here are some testimonials from Ninja 650 owners with under 1,000 miles on the clock:

• “My Kawasaki Ninja overheats in intermittent traffic. I checked the coolant levels and they are fine. I checked the bike at 600 miles and I only have 800.I took the bike to the shop and the fan wouldn't come on. They ordered a new part and [repaired] it under warranty.”
• „My 2015 Ninja 650 used to overheat. I found that all 15 specifically had a faulty temperature control unit that could burn out. Turns out I had to replace mine and had my shop install a custom switch for the fan. Essentially, you connect the fan to a controller, and then you can turn the fan on and leave it on while driving without worrying about overheating.„

5. The Kawasaki Ninja 650 will not idle

Modern ninjas have a sensor that detects when the bike is in neutral.

The sensor has two functions:

1. Tell the display that the bike is in neutral so that the N light illuminates on the shift indicator.
2. Tell the ECU that the transmission is in neutral and not in gear so the ECU can start the motorcycle.

When a Kawasaki Ninja's neutral sensor goes bad, it thinks the bike is in gear even when it's in neutral.

Not only does this prevent the neutral light from illuminating, but it also means the ECU is preventing the Ninja from starting.

6. Kawasaki Ninja 650 without acceleration

Some Ninja 650 riders claim their bikes tip over but don't accelerate when you step on the gas pedal. In these cases, the Ninja has a problematic throttle position sensor or the throttle bodies are not properly balanced.

Here is an example:

„I have a brand new 2009 Ninja650r with 10,000 miles and all maintenance is up to date and to factory specs per a store bought genuine Kawasaki repair manual.

I have a problem at 4000rpm or below in 4th gear (or 3rd and 5th gear) while driving when I twist the throttle a little; Either way I have my doubts. If I drop the revs to 3500 and keep the accelerator steady, it locks up almost like it's stalling."

Some riders claim that the problem is factory pre-2011 models and cannot be fixed without installing a positive crankcase ventilation upgrade system to reduce crankcase vacuum and increase the motorcycle's RPM and torque.

Others claim that the improvements to the air intake and exhaust are enough to increase rev lag.

Still, the consensus appears to be related to bad throttle position sensors and poorly tuned throttle bodies, as not all pre-2011 Ninja racers have static rpm issues in the low throttle range. In fact, most of them say they don't.

7. Kawasaki Ninja 650 will not start

If you crawl through the Ninja forums you will find no shortage of posts like these:

“Sometimes when I'm stopping at a stop sign or a red light and I'm pushing the clutch to click first to start and it doesn't work and then it goes into neutral and I have to kick it to go there always get back into 1st boarding."

In some cases, the problem with the Ninja 650 not shifting is caused by low oil level or bad, burnt or contaminated oil that continues to flow through the bike's motor long after the gear change.

In other situations, the shift linkage is too tight.

And finally, theorists like this Kawasaki rider seem to think that a faulty positive neutral finder is the cause:

“This has happened to me, usually if I don't shift into first gear before stopping. I release the clutch a bit and can start. I've read elsewhere of people having the same issue, most likely positively neutral searchers; You just have to make sure you're first in line before you come to a complete stop."

8. Kawasaki Ninja 650 no idle

One of the most common issues we have found in first-time Kawasaki Ninja 650 riders is low idle issues.

In some cases, low idle will affect engine performance, while in other cases, the Ninja 650 will have difficulty starting.

The Kawasaki Ninja 650 has a small dial on the right side of the bike, above the clutch housing. Recommended idle speed varies by model year but is typically around 1300 RPM.

Riders who are unaware of this setting sometimes accidentally change throttle settings, unaware that they can fix it just as quickly.

9. Kawasaki Ninja 650 keeps shutting down

Some Kawasaki Ninja 650 owners have reported problems with their bikes stalling and stalling while driving.

The problem is often accompanied by frequent breakdowns.

In some of the instances we found documented in online reports, the bike's RPM's increased, causing the Ninja's speed to fluctuate regardless of rider input.

It has been reported that the problems were caused by clogged injectors or dirty air filters in most cases and leaking vacuum systems in some other cases.

10. Kawasaki Ninja 650 battery keeps dying

Quite a few Kawasaki Ninja 650 owners have reported battery drain issues.

In some cases, the battery and lights are discharged while the driver is driving, while in others the depleted battery is detected upon starting.

Here is an example of the above scenario as it happened on a 2014 Ninja 650:

„So on the way home from work today the bike behaved strangely. The battery light came on for a minute or so, as did the check engine light. When I stopped, the bike didn't idle as usual or slow down, the display wouldn't turn on or show RPM, speed, etc., and then went black. So I got out and pushed it onto the curb and hit a pothole with it and dropped it on the right side. I towed the bike home and even charging the battery I couldn't get the fuel pump to work or the display to light up during a charge mode, be it a 2, 10 or 50 amp charge. . No corrosion on the lugs, not a hint of rust anywhere on the wheel, it has been garaged and never ridden in the rain.”

• The Kawasaki Ninja 650's battery is hidden under the bike's seat. In some cases, the sweltering heat was enough to overheat the battery while charging.
• In other cases, a faulty ESC/regulator will overcharge the battery.
• Finally, some rider reports admitted that their Ninja was being charged at a higher voltage than the battery required.

All of these scenarios boil the electrolytes in the battery, causing it to continue dying.