The standard or naked little ripper called the Honda CB650F hit the streets in 2018 after jacking its engine and most of its technology from the legendary mid-sized sportbike, the CBR650F.
We don’t blame Honda for reusing the motor—its 649cc, liquid-cooled, inline-four engine was enough to push a street fighter; putting it on a naked bike seals the deal as far as efficiency and performance go.
Honda upgraded the CB650F’s airbox for power by running its cables and wires differently to give it more airflow response. But what are the most common problems with the Honda CB650F?
Don’t ride off; read on to find out!
Table of Contents
1. White Substance Leaks From Oil Seal
This isn’t precisely an issue, but since the forums are littered with CBR650F riders who consider it to be one, we figured we’d shed some light on this familiar happening.
You might catch a glimpse of a white chemical leaching from your CB650F’s head gasket’s oil seal.
- First, inspect your oil and coolant to make sure nothing’s leaking.
- Make sure your oil and coolant levels are consistent; if they’re low, top them off before moving on.
- If you see a white residue, notice if your exhaust smells sweet. If it does, use a turkey baster to take an oil sample and see if it’s milky. There’s a more noteworthy problem—you need to take your 650F to a Honda technician to inspect.
- Now, if you see the powdery white residue around the head gasket, but your oil looks fine, it’s probably just the rubber gasket curing.
The white, rubbery substance you’ve been encountering is the essence of the rocker oil seal leaching out of the rubber—it’s to be expected on these models. Clean your CB650F up with a dry cloth once in a while; eventually, it will stop.
So, what’s the white substance on the head gaskets of your Honda CBR650F?
There’s a chemical called plasticizer added into the seals to ensure they’re flexible enough to seep into the crevices.
The additives drain the rubber seal as the rubber cures from the engine heat and weather, leaving the powdery white substance in the broad area.
Miles has nothing to do with whether the substance leaks. The plasticizer has to leak out and run its course. It will stop leaching in time.
In short, there’s no reason to be disturbed by the appearance of a powdery white substance on your CB650F—there’s nothing wrong with your faithful naked steed, so clean off the white chemical essence, jump back in the saddle, and let her rip!
2. Intrusive Rattling/Whistling Sounds
The most common complaint regarding the Honda CB650F that we found online involved two different strange noises.
CB650F owners describe the first sound as a vibrating rattle noise, usually high pitch—the sound of metal on metal friction.
Now here’s where it gets weird; most of these riders claim the sounds don’t happen when the bike is in neutral.
- The reason the metal rattle doesn’t happen in neutral may be that the vibration is connected to the bike’s revs.
- The high-pitched metal-on-metal vibration is most pronounced in 1st and 2nd gear.
- More than a few CB650F owners have a different theory, claiming the high-pitched vibration occurs when the bike’s in high gears due to wind.
- To be clear, the metallic noise in question is distinct from the C650F’s normal engine roar—this is a high-pitched buzzing sound.
I finally came across a Honda-enthusiast who shed some light on the situation; it turns out this first noise is the sound of the key vibration in the ignition.
- Some 650F owners discovered that wrapping a rubber vacuum tube around the top of their key would prevent the metal buzz from happening, enforcing the theory that the sound is coming from the key.
- I dug up one consumer report claiming the rider saw the key vibrating along with the rhythm of both the RPMs and the high-pitched rattling.
CB650F owners have described the second noise as a high-pitched whistling sound, very different from the buzzing rattle described above.
This noise, they say, seems to be triggered by speed more than revs, manifesting at 45 mph.
The culprit for this weird whistling sound is simply the wind running over the gauge cluster.
Unlike its fairing-laced sportbike sibling, the CB650F is stripped down and, well, naked.
- One of the most common complaints about the CB650F involves the lack of a fairing and the whistling sound caused by the wind flying over the instrument cluster.
- Some riders solve the problem by installing a windscreen, either from Honda or an aftermarket accessory manufacturer.
- While some riders claim Honda’s OEM windscreen add-on only offers slight protection from the wind, most riders agree it does the job of preventing the CB650F’s weird whistling sound.
The Honda windscreen was engineered specifically to work with the CB650F, complete with an install kit straight from the factory.
It functions by redirecting the air over the front end of the motorcycle.
- Installing the windscreen means taking off the bike’s headlight.
- Still, it’s a simple job you can do yourself at home.
- Although the cluster whistle is what I like to call a cosmetic problem, if it’s ruining the experience of riding your faithful naked steed, it’s likely worth the time and money to pick up a windscreen and kill it once and for all.
- Step 1: Install the brackets.
- Step 2: Use the four bolts and the various plastic and rubber washers with the install kit to mount the windshield to the flyscreen brackets.
There are numerous windscreens available online that not only kill the annoying whistling sound but also trick out your straightforward naked bike in different ways, adding a level of customization to your CB650F.
3. Engine Sputters in Cold Weather (Solved)
This subsequent complaint is pretty standard; since it’s based on a simple misunderstanding we can quickly clear up. We dedicated this next section to it.
Riders first notice this “issue” when they disengage the clutch by pulling in the lever while at cruising speeds. CB650F riders hear a weird “metal fan” noise generating from the engine.
According to these real-life consumer reports, the following symptom to manifest is engine sputtering.
- The common denominator in all these cases indicates the culprit is practically red-handed—it always happens in cold weather.
- After some troubleshooting, CB650F riders started noticing that, in fact, it only happened in the cold.
- If these riders let their bikes warm up to spec operating temp before riding in cold weather, it wouldn’t happen at all.
The straightforward truth is that your mid-sized Honda naked bike packs a liquid-cooled inline 4-cylinder 649cc engine that is as dependable as anything in its class, so why the sputtering in cold weather if you don’t let it warm up?
In hot weather, liquid cooling has its clear advantages. That said, it’s a different story when the climate drops to severe cold, not to mention inline-four motors don’t like the cold in general.
- Allow your CB650F to warm up for 5-10 minutes before riding when it’s cold outside.
- This warm-up period gives your pistons and coolant a chance to reach Honda’s spec-ideal operating temperature before you make the motor work.
- Forcing cold pistons to work hard is the cause of cold-weather-sputtering on the CB650F; running at the suggested engine temperature is the solution.
4. Routine Battery Failure (Previous Owner Negligence)
There’s nothing more frustrating than sitting on your CB650F, all geared up and ready to hit the town, and then the bike doesn’t start.
To be clear, this isn’t a common problem specific to the Honda CB650F; it’s a popular choice for a first bike, and we’re here to help riders of all levels.
We’ve encountered numerous confused CB650F riders in the forums, so we figured we’d include a quick review of battery troubleshooting in this piece.
Symptom of Battery Failure on a CB650F
Here’re symptoms of a failing battery on a CB650F bike:
- CB’s engine power supply starts to dip slowly for a few weeks.
- Your CB650F’s lights and gauge cluster flickers randomly for no reason.
- When a worn battery reaches critical condition, your CB650F’s engine will randomly die, coming back to life in rhythm with the flickering lights and instruments.
Inspecting the voltage of your CB650F battery is part of regular bike upkeep. All batteries die eventually. Forgetting to check your battery voltage leads to your poor naked Honda’s battery passing without warning.
When experiencing electrical issues on any CB650F, any motorcycle, for that matter, the battery is always the first troubleshooting step.
Batteries die over time.
Observe your gauge cluster during ignition if you suspect a failing, old, or worn battery. If the battery is bad, you’ll see it dimming and flickering.
A parasitic draw can destroy any battery without warning—the battery never has a chance to rest and recharge if it’s being drawn from.
Replace your CB650F battery at the first sign it’s worn; keep it charged to avoid dimming lights and power loss.
NOTE: To reiterate, there’s nothing defective about Honda’s stock battery. The cases of parasitic drain we encountered regarding CB650Fs were often the result of poorly installed or mismatched aftermarket upgrades.
General Pros and Cons for the Honda CB650F
Here’re some pros and cons of the Honda CB650F:
With the CB650F, Honda proves the sweet spot between style, performance, and reliability.
The CB650F is an excellent choice for new riders and people that started on a small standard bike and are ready to graduate to something more mid-range.
The CB650F is fun to ride, so fun that in many cases, amateur riders hold on to their naked little buddies to keep as in town commuters, guest bikes for visiting friends, or in some cases, learner bikes for the next generation of moto-maniacs.
- White Substance Leaks From Oil Seal
- Intrusive Rattling/Whistling Sounds
Engine Sputters in Cold Weather (Solved)
Routine Battery Failure (Solved)
What Do the Reviews Say?
What’s the Resale Value of a Honda CB 650F?
ⓘ 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.