A motorcycle parked in front of a tent on a pleasant green campsite

Home Repair And Restoration

Z250SL Headlight Crazing

Problem Date - Leading up to 12 September 2020

By Ren Withnell

Sharon is crazy. No, hang on that is true but that's not what this is about. Try again. Sharon's headlight is crazing. That's better.

Sharon's Kwakker 250 is now about 4 years old. Around 2 years ago we noticed a few minor "cracks" in the lens of her headlight. We monitored this but it didn't seem to be a problem. Then more cracks. Then more. Then more. Hmmmm. This could be a problem. It is a problem but with Sharon having far more important problems to deal with (a multitudinous compendium of health issues for her and her daughters) this problem hasn't been top priority. 

We did make an initial approach to Orrell Motorcycles where Sharon purchased the bike. Bearing in mind the bike was out of warranty they weren't unpolite or dismissive, but they weren't keen to help.

Sometime in early August there was a brief moment amidst the chaos of Sharon's life that allowed us to get some snaps of the headlight. I decided to email Kawasaki UK directly and appeal to their "customer service".


My partner purchased a Z250SL in 2016 brand new from Orrell Motorcycles (https://www.mcobikes.com). We've been very happy with the bike but around 2 years into the ownership we noticed a few cracks in the headlight lens. They were small and we put them down to stone chips. However as time has rolled on this is getting worse and worse to the point we fear the lens may disintegrate. I suspect this is due to the heat of the 65 watt bulb as I suspect it was originally designed for the Z125 which may have a 35 watt bulb. This damage is not crash damage as it started on one side but is spreading slowly but surely across the lens.

We have enquired at Orrell Motorcycles about what we should do. Unfortunately as the bike is out of warranty they don't want to know. As such I am escalating this to Kawasaki directly. While I understand the warranty is expired I am surprised that the lens should have gone this way in 4 years, I'd expect it to last a lifetime. Please could you advise me as to what we can do to get this remedied. 

I have attached pictures to help clarify the problem.

Many Thanks, Ren Withnell.
Ren - The Ed.

Across the lens are crack and marks spreading out
More fine lines in the lens like crazy paving
From above the fine lines radiate out from the sides of the lens
We see a focal point to the crazing on the left side of the lens


I immediately received an automated "thanks, someone will be in touch" reply then I received this reply 2 days later


Good afternoon Ren

Thank you for writing to Kawasaki Motors UK.

Whilst we are sorry to learn of the issue which you have experienced with your machines headlamp, we appreciate your time in bringing this matter to our attention.

We are confident in the design and manufacture of our vehicles but appreciate occasionally, components may fail unexpectedly. We also appreciate that you may not expect such an item in your vehicle to need replacing at this period of time and it is of course disappointing that this has happened.

As you stated in your email that you believe that the cracks first appeared were possibly due to stone chips this is not something that the warranty would of covered.

Having checked records available to us I can confirm Kawasaki Motors have not experienced any common failures of your machines component based on records available to us throughout Europe when compared to the volume of machines sold.

Kind regards


Technical & Customer Service Group
Kawasaki Motors UK


I see. So that'll be a very very vague and non-committal "Yeah, we ain't seen that on other bikes so stone chips gone mad. Unlucky". 

Is it? What is this? What is going on here. 

Stone chips? Naaaaah, I don't think so. I've seen stone chips and they appear individually as each stone strikes. This crazing is spreading across the lens slowly but surely.

Chemicals. An online search suggests certain chemicals such as thinners and solvents can cause this. Sharon assures me that she only uses regular cleaning products like Muc-Off, waxes and soaps. I can't think of any reason she would use a harsh chemical anyhow. 

Heat. I can't help but feel that the plastic in this particular individual instance is the problem, but there's more on that later.

With around 4 weeks to go before our Norn Iron trip we meet up at Orrell for a ride out. It's always worth remembering that getting things done involves talking to the RIGHT person. As such I ask one of the team at Orrell Motorcycles to look at the light and form an opinion as to whether or not this is stone chips.

My plan is to get a Kawasaki official to agree with me these are not stone chips so I can go back to Kwak Customer Service with this second opinion. Indeed D, the team leader, agrees this is not due to stone chips. More than just agreeing with me he agrees to contact Kwak himself and "see what he can do".

The problem with this is the wheels turn very very slowly. We are but one insignificant problem in a plethora of problems the Orrell team will deal with each week. The same applies to Kawasaki UK too. With one week to go before we (hopefully - grrrrr Covid) depart to NI there's nothing forthcoming from Orrell or Kawasaki. To be honest I didn't expect there would be, I await to see if there ever will be.

So, what to do with regards Northern Ireland. On the one hand the lens is crackling ever more but the lens, at present, seems structurally secure. My concern is with the long rides, whatever is causing this issue will be enhanced and it is possible the cracks could join up and the whole lens falls out. This would rather spoil the trip.

A new light unit (the lens comes as part of the sealed light unit) can be purchased from the Far East for around £170. A genuine item from the UK can be had for £290. Holy poop. There are absolutely none to be found used in the UK at least. I offer to fit a 6 inch chrome "Bates" headlight I have spare but this is met with a resounding "NO!!!".

But. With a little digging and a little comparing of parts numbers and I am confident the Ninja 250 SL, the Z125 and the Ninja 125 all share the same headlight. By sheer luck I manage to find a Ninja 125 headlight on Ebay from Yorkshire. For £137 delivered. It's a good square kick in the Netherlands but they have one and we can have it in time for our holiday.

The light is duly delivered intact and in good condition, it is indeed a match save for a rubber grommet or two which we swap from the crazed light, and, as they say, Robert is your father's brother.

The rear of the Ninja 125 and the Z250SL headlights and they are almost identical
Ninja 125 on the left, Z250SL on the right. SNAP!
With the headlight removed it looks like a tangled mess of wires and brackets
It looks difficult to change but it's actually quite simple.

So, am I correct regarding the Z125/Ninja 125 using a 35 watt bulb, and the 250 using a 55/60 watt bulb and thus overheating the headlamp? No. The Ninja 125 light came complete with a bog standard H4 55/60 watt bulb. My assumption is incorrect.

What do I suspect has happened? I suspect Sharon's light was indeed faulty from the factory. I suspect when the plastic lens was glued to the back section something somewhere was marginally out of place causing a degree of stress across the lens. With endless heat cycles from the bulb this stress started to cause this crazing.

I fully accept this could be wrong, merely the guessings of an uninformed amateur. I am open to suggestions from the collective knowledge. 

See also Sharon's Headlamp Saga Continues

Click here and share your own motorcycling woes.

Reader's Comments

Upt'North said :-
It's air Ed, air. Well it might be.
Motorcycles are parked up often in cold damp conditions and often for long periods of time. Months in some cases. Then MM or Ed comes along hits the starter button and voila, we have light and with light we have heat.
Now when you heat damp air you get condensation and increase in pressure within the headlight if not vented. Hence the stress fractures will form.
This is my theory but one which I feel is more valid as this particular motorcycle is always under a rain cloud with MM at the helm.
Although I don't think it's something I can recall seeing before.
05/10/2020 15:38:15 UTC
Upt'North said :-
Wouldn't happen on a Honda.
05/10/2020 15:39:49 UTC
Upt'North said :-
It's a thing....... "spider cracks", apparently.
What was up with good old 7 inch sealed beams?

Posted Image
05/10/2020 15:50:31 UTC
Ren - The Ed¹ said :-
I haven't yet checked Madam Moisture's headlight for an airtight seal or a vent. But then it uses a standard H4 bulb which while a secure fit I struggle to believe it would be air tight, or at least pressure tight.

I did look at fitting an LED bulb which would greatly reduce the heat output and also the electrickery consumption, relieving stress on the alternator and regggy reccy. Apparently you can't because the headlight was homologated with incandescent bulbs and to fit and LED would, I am told, negate this homologation.
05/10/2020 16:45:08 UTC
Upt'North said :-
I know the LED headlight issue is much discussed but I fail to see how the current bulbs would pass the Mot test, they are undoubtedly bright and white but the beam direction seems poor. No doubt they will improve, but you also need room for the cooling fan although I do believe there is a new bulb which incorporates the fan in the bulb side.
I agree, the H4 would not provide an airtight seal.
I suppose my suggestion is that you are effectively boiling a kettle in the headlight if parked for too long.
05/10/2020 16:57:53 UTC
Bogger said :-
If you let me have the old headlamp I'll rub it down and re-lacquer it for you and we can see what that does.

Don't worry Ed it'll be at a price you know and understand. As in free. Let me know.

05/10/2020 19:54:22 UTC
nab301 said :-
Searching forums suggests the lamps do crack like your example , but I don't think it's moisture in the headlamp , the bulb would just explode if it was damp . I had a 500 Honda for years and the plastic lens never cracked although the reflector did come loose just before i sold it . Car headlamps tend to turn opaque or yellow but this can be polished out easily , I've never seen them crack like that . Can you check the output of the alternator (charging voltage) incase it's overcharging and possibly running hotter than it should?
05/10/2020 20:58:39 UTC
Ren - The Ed¹ said :-
Upt' - I see things about LED cooling etc but not speaking as an expert it makes no sense. LEDs run cooler, Shirley? If a light is designed from the outset to take a certain LED bulb it *should* work just fine. There still doesn't seem to be a H4 style LED bulb where the light emanates from the same point as the incandescent bulb which of course messes up all the angles of the reflector. However even lights designed from the outset to run as LED can and often do dazzle. LED is a harsh, unforgiving kind of light.

As an aside the 500 has an LED light and it is, well, erm, barely mediocre. But it doesn't have a fan for the lights.

Bogger - to my eye it looks like the cracks go right through the lens. Subject to her worshipful overlord's most gracious permission through I'd be both interested and happy for you to try. I could bring it to your place in Warrington, drop it at your door, step back 40 paces and we could wave at each other from a safe distance. You'd then need to sterilise and disinfect the light. Seriously though, you are more than welcome to try.

nab301 - It's worth a quick dab of the multimeter to check innit. Would you believe Sharon even has a multimeter and it's fancier than mine. Pffffft.
06/10/2020 08:14:25 UTC
Bob said :-
Having spent a few years working with injection moulded products I would say it's just a poor quality batch of material that was used when your particular headlight was made.
The cracks are down to heat, not pressure, the sealed rubber boot on the back of the headlight buld is just there to keep out moisture and if you look at it it will probably have a breather flapper valve as part of its design.
As Bogger suggests the lens might be recoverable with polish and lacquer.
06/10/2020 08:15:59 UTC
Bogger said :-
Just let me know Ed.

06/10/2020 08:19:37 UTC
Ren - The Ed¹ said :-
Sharon will give Kwakker another nudge. If we get no further with them then it's all yours. I still can't believe she wouldn't let me fit the Bates though, I mean it worked out fine on the NTV 600 Revere.
Posted Image
06/10/2020 16:32:49 UTC
Upt'North said :-
I hope you make a better job of the weather than that headlight, now that is goppin'.
06/10/2020 18:27:40 UTC
Ren - The Ed¹ said :-
Goppin!!! I haven't heard that in a while. It did give the bike a certain kind of charm doncha think? Look I couldn't remove the old headlight as all the wiring is in there and there's zero space in the Bates. It were a long time ago before I'd honed my bodgin' skills. Erm. Look it blooming well worked just fine and I still have it for when the super expensive LED sealed unit headlight on the 500 gives up. Now, that, that will look REALLY GOPPIN'. I'm so excited!
06/10/2020 20:04:15 UTC
Bob said :-
Eeek, just eeek.
07/10/2020 10:27:56 UTC
Ren - The Ed¹ said :-
Traumatised by my beautiful handiwork Bob?
07/10/2020 20:40:01 UTC
Rod said :-
Hello! First of all, I must congratulate you for this great website! I'm also a happy owner of a 2015 z250sl. I use this little bike for commuting and it's great fun.
But regarding this headlight problem it's just Kawasaki fault. My lens looks much worse than yours, I'm just waiting for it to complete crack. Firt I thought it was stone chips, but it began spreading all over the lens. Now that I saw how your lens looks like, I'm sure this is just poor design from Kawasaki.
16/10/2020 11:38:26 UTC
Ren - The Ed¹ said :-
Aha! Thanks Rod, so it's not just Sharon's headlight is it. As Bob suggests above it seems quite likely they had a bad batch. Sharon's is a 2016 registered bike but it could have been made anytime. Also the lens could have been made anytime. I'm wondering if there's any information in the moulding that could give us a batch number or some other indication.

I can't get my hands on Sharon's old headlight at the moment to check. Rod, it'd be hand if you could drop me an email - ren@bikesandtravels.com - to see if there's any way we can find a connection between these respective headlights. Might be able to use this info to push Kawasaki a bit.
16/10/2020 12:06:45 UTC
Keith m said :-
REN: There is often date stamp moulded parts like this. Have a look on the black part when you are allowed.
17/10/2020 18:43:15 UTC
Ren - The Ed¹ said :-
Keith m - yeah that's exactly what I'd like to find, that or a batch number. Rod has kindly emailed me so I'm in touch with him and we'll see what we can see. Maybe we can do something maybe not, but it's worth a look ain't it. Sharon has a connection with someone who may have Covid so we're all keeping a safe distance until we get further details.
17/10/2020 19:05:46 UTC
Alexis said :-

I'm from Bangkok and this is a common SL problem; It's the headlight, it's too hot. Kawasaki usually just changed it for free here if the bike is still under warranty, if not, people just scrub it with fine sandpaper (same as restoring a car's headlight), polish it, then apply some clear UV coating into it. Changing to LED headlight keeps the problem from ever happening again.

Know that it's not the headlight that is cracking, it is just the uv coating peeling off because of the heat of the oem bulb.

Those who's headlight hasnt peeled off yet better change to LEd headlights as soon as possible.

Any H4 LEd will fit.
09/11/2020 08:23:13 UTC
Upt'North said :-
Good information Alexis.
09/11/2020 09:11:20 UTC
Ren - The Ed¹ said :-
Wow!! Thanks Alexis, really good information. What would be useful is if you could point me to some more information about this. Forums, recalls in Bangkok or anything else like that. I'm looking to convince Kawasaki here in the UK that this is a problem.
09/11/2020 15:03:18 UTC
Alexis said :-

No recall was publicly announced, guess they just wait for people to come and complain. What happens is that most people who don't ride that much get this problem right after the warranty is gone. If the warranty is still valid, you'll have to wait a month for a new free headlight. If warranty is expired, they'll offer to sell you a new one and it's not cheap, also need to wait a month, so people opt to have it scrubbed and polished. I'm gonna try to find some article or anything about it and share it here. Most of the complains are in our SL Facebook group which is private and also not in English.

Below is a screen grab of the same problem taken from our FB Group page. This was just yesterday Nov 9,2020.
Posted Image
10/11/2020 03:14:04 UTC
Alexis said :-
Heres a link of a guy in Thailand sanding his SL's headlight because of the same problem.
10/11/2020 03:21:23 UTC
Ren - The Ed¹ said :-
That is absolutely fantastic information Alexis, thanks you so very much. Sharon and I will put another email together to Kawasaki UK and see what they have to say. I'm still not expecting they'll happily send a new light, fortunately we are not in a desperate situation. It will be an interesting insight into Kawasaki UK's attitude towards the long term care of their product.

If we unsuccessful with Kwakker UK I'll be taking up Bogger's offer to polish the headlight. I'd like to be involved, we might have to wait for this damn Covid situation to sort itself out.
10/11/2020 09:25:26 UTC
Upt'North said :-
Sorry Alexis, can't watch it, it's brutal. No, it's BRUTAL.
If anyone is tempted to carry out the procedure please use painter's tape to cover the surrounding area and ensure other areas are covered to prevent marking. Also when using a wet and dry sanding method use lots of water and spray both the area and paper off regularly to prevent larger particles digging in and causing deep scratches. An old kitchen spray bottle well rinsed will make a good sprayer and cost nowt as well.
Sand from side to side in straight motions, don't go round in circles and I suppose the headlight could be removed if easier and the right shape to hang on to.
10/11/2020 12:57:19 UTC
Alexis said :-
LOL didn't even watch the video. Just posted that to show Sharon's case is not an isolated one. Now that I've watched it, I agree it wasn't the right way to do it.
10/11/2020 13:42:48 UTC
Ren - The Ed¹ said :-
And here's me, with a coarse metal file and a sheet of 80 grit sandpaper about to make a start! Phew, glad I checked here again. I suppose I might as wel unplug the bench grinder too then.

On the Z250SL the light is remarkably easy to remove once you've worked out the fasteners and bolts.
11/11/2020 10:22:14 UTC
Bogger said :-
The offer still stands Ren, about me getting it 'painted' for you FOC

11/11/2020 21:38:37 UTC
Ren - The Ed¹ said :-
Cheers Bogger. Don't hold your breath though I'd like to see where the Kwakker UK tale leads us first.
12/11/2020 08:22:13 UTC
Phil said :-
My pal has one a 2018 model and his light is crazed too.
07/04/2021 19:00:48 UTC
Ren - The Ed¹ said :-
Grrrr! Kawasaki telling us it's the first they've heard of it. Lying swines.

Bogger, I might nudge Sharon see if she wants you to have a go a polishing the crazed lens.
07/04/2021 20:31:27 UTC
Dave said :-
I'm living in Chiang Mai and also experiencing crazing, glad I'm not alone in this crazing world. But I'm curious to know if anyone just replaced the headlight cover? Do we really need to replace the whole unit?
09/02/2022 13:04:24 UTC
Ren - The Ed¹ said :-
The headlight "cover" or lens is glued to the rest of the light so I'm sure it is possible to unstick it but you won't be able to buy a new lens so it seems pointless.

BUT Fear not. The headlight unit is the same as the Z125 version AND we have discovered that the cracking is ON THE SURFACE of the lens. You can choose to leave it be OR you can get your friendly neighbourhood bodywork type person to polish the living heck out of it. See the link to see what Bogger's team did for Sharon's lens
09/02/2022 17:16:19 UTC
Dave said :-
Thanks for the advice, I'll definitely have to purchase a new or second-hand headlight unit. BTW - An awesome website and appreciate the valuable info!
11/02/2022 07:46:20 UTC
Ren - The Ed¹ said :-
Cheers Dave :)
11/02/2022 09:12:24 UTC

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