No spark diagnosis and Explanation (GY6)

In this video we diagnose a Chinese scooter with a GY6 engine that doesn't spark.
I also explain how the system works in a easy to understand way, so you'll be able to fix your scooter yourself.
I hope the video is helpful !

[@Masso1973]

Next: a helicopter

[@remusracingro3884]

He'll fix it, surely .

[@SurvivalInFlames]

It’s just lift vs. drag and rotation😂🤣

[@axilleas]

Let’s upvote this comment and make it happen

[@justinhayward5027]

Area 51 craft!

[@gostodiag7615]

😂

[@Czechbound]

Whether 4 wheels or 2, the logic of your approach and your clear explanations why things happen, or don't happen is why we're all here. Great result !

[@Diagnosedan]

Thank you

[@hightttech]

A fix is a fix 👍

[@andyguest6543]

I don't care what you are fixing, I always learn from your channel. Love what you do, I know you are a busy man but I wish we could have more videos

[@Diagnosedan]

Thanks for your great comment

[@markmagee2382]

Suddenly I don’t feel so stupid, brilliantly explained and presented, my night is made with a diagnose Dan video 👍

[@Diagnosedan]

You are not stupid, sometimes we have a lack of knowledge but that has nothing to do with stupid

[@benjaminrich9396]

As a guy myself who diagnoses and fixes two wheel stuff as well as four - nice to see some 2 wheel content. (They get a bit trickier than scooters mind...) :)

[@Diagnosedan]

Something different for a change 😁

[@benjaminrich9396]

A quick (ish) tip: I use scopes, I love them, and I teach others to use them - for four wheel stuff and two - but Dan's right in that not everybody will have one. Or even if they have one, at the side of the road they might not have one with them. Dan is also right (indeed he shows it on the video) that due to both the waveform characteristics of the 'pick up' (a two-wire variable reluctance type 'crank sensor' of sorts in car language) and the way digital multimeters work, you can't get a good read with a DVOM on these kind of signals. Also with the capacitor charging output. Even when Dan sets the multimeter to AC the reading is way off. This is because on AC the meter is expecting a sine wave. So the characteristic shapes of both the 'pick-up' (the timing sensor is you will) and the 'capacitor charging coil' won't be accurately gauged. (incidentally though, if instead you're testing the AC output from the stator that goes to the reg/rec of a scooter or bike - single phase or three phase - with the connector at the reg/rec disconnected you usually CAN use a normal multimeter on AC volts to measure that - near enough.) Dan is right in that a lot of people sort of use a multimeter on AC and kind of learn a rule of thumb for these 'not actually what the voltage is' numbers. For example, on the working stator his capacitor charging coil output at cranking had an actual scope-measured peak voltage of +120V, but only read 77v or so on the meter set to AC, and he stated a rule of thumb that 50 - 100v on the multimeter (set to AC) was considered good. Similarly, on the pickup it scoped at around 4V for the positive peak voltage, read around 0.4v on the multimeter (set to AC, with multimter neg lead on battery negative, NOT on the earth/other wire from the stator btw) and he states 0.4V to 1.5V AC is good. This is fine to a point. But some stuff 'spikes' so quick even this 'known flawed' technique with the AC won't work. So rather than sort of guessing with rules of thumb like that, what is VERY cheap to make (many will know this trick but a lot won't) is a "peak Voltage adapter" for your multimeter. You can literally make one of these with a Diode, a capacitor and a resistor. That is all. You can add other stuff to complicate it, reset it quicker etc, but honestly those three components will work fine. I have made dozens of these. The details are easily findable online, just google it. DO NOT buy one. Just make one. These 'capture' (for long enough for you to read off your multimeter set to DC Volts, before the resistor bleeds off the cap) the PEAK positive voltage. If you really want you can make a version that captures the negative peak, but the positive peak voltage is usually the info you're after. They work with the under 5V of the pickup and ALSO the 100 to 200V you get from the output which charges the capacitor in the CDI. Interestingly, the way CDI works (either so called AC or so called DC) kind of uses this same diode then capacitor set up itself to capture the voltage too, only by way of a thyristor or later electronics it's then actually using the stored charge to put through the coil primary when told to, rather than just holding so you can read it on your multimeter. :) NOTE. Remember to factor in the forward voltage drop of whatever diode you use. This means the initially stored voltage in the cap that your multimeter reads will be the actual voltage MINUS say, 0.6-0.7V. When you're seeing if the Capacitor Charging coil is peaking at spec, if you're looking for say 120v, an error of around half a volt is no problem. But if you're comparing against a known spec this offset IS a fair amount of the much smaller voltage you'd be looking for on the pick-up. ALSO, remember if you're using a Peak Voltage Adapter your multimeter is now set on DC. As you're measuring the DC voltage stored in the capacitor of your adapter. This is simply the positive half of the waveform as the diode has 'half wave rectified' if you will. If you look at a lot of particularly Japanese motorcycle factory service manuals, they will often give the peak voltage minimum requirements for a number of things: the pick-up (even on non CDI bikes too), the CDI charging coil output (on AC CDI bikes), even the primary spike on the ignition coils too (which you're definitely not going to get with a voltmeter on AC). As a 'poor man's scope' I've even checked ABS sensors and all sorts using one. Now yes, as anybody who does any diagnostic work can tell you, occasionally of course you're interested in far more than simply the peak magnitude of the positive voltage of a 'crank sensor' pick up etc's output. Bad pattern, wired back to front, cam crank correlations etc etc. But for side of the road "why won't it run?" diagnoses on bikes and scooters, often just knowing the peak voltage of the pick up (and in Dan's case here from the Capacitor Charging Coil also) can find your problem. Cheers, Ben (B.R.Repair Services)

[@Equiluxe1]

An oscilloscope gives the peak to peak voltage the dvm gives rms voltage so will always read lower whatever the ac source.

[@Diagnosedan]

Hi Ben thanks for your great comment. I guess there are quite alot of kids working on their scooters and at least they have something to work with. I guess most have access to a multimeter. Great tip btw😁👍

[@mrmonster7340]

This may not be what you usually make videos about but you just dropped the best scooter vid out them for no spark well done

[@rorybyrne975]

Fair play to you for not holding plug the second time round. 😂😂 We would get a laugh 😂.Good work

[@Diagnosedan]

🤣🤣👍

[@JohnSmith-wb6kq]

Hiya Danny boy haha, mate I'm sure I'm far from the only one who really really appreciates the time and effort you put into making these videos, and combined with your natural ability to convey often quite technical info in a super easy to understand way for everyone is awesome, your videos are EXCELLENT, keep up the good work, your customers appreciate it, a fan from a land down under 🙂

[@Diagnosedan]

Thank you John, filming a diagnosis can turn a one hour job into half a day. But all the great comments make it worth it😊

[@khalidgamerftw8954]

I never thought i would ever watch diagnostic dan repairs a scooter video i thought he is to smart for this. now my stupidity level is lower.

[@markblundell9461]

A great detailed diagnosis of this scooter Dan. This will be a great help to a lot of folk trying to fix their own problems.

[@Diagnosedan]

Thats exactly why i decided to film this one, hopefully it can help some kid trying to fix their scooter

[@AW_DIY_garage]

Dude. Thank you for walking through that so logically and clearly

[@majedalmorabee2593]

Cars, scooters, e bikes even toy cars are always fun and informative to watch on your channel. Just keep bringing us those quality videos.

[@Diagnosedan]

Thats good to hear, thanks for your nice comment

[@rsbreeze]

Excellent video. Helped me troubleshoot a Kymco Mongoose 70 ATV.

[@kastamD]

I always like your explanations. Keep up the good work!

[@Diagnosedan]

I will, thank you

[@roberthenuber5958]

Had a Cushman scooter and learned about magnetos and spark the hard way...was 15....went on to become an electrical engineer. Fascinating. Your channel challenges are highly anticipated.

[@Diagnosedan]

Thats a great career, well done!

[@thedannyboy64]

Another great video, and I wouldn’t mind seeing more motorcycles, nice one Dan 👍🏼👍🏼

[@Diagnosedan]

I wasnt sure if you guys would want to see this

[@ben7020]

Dan didn't have to climb under a dashboard- so its a good day for Dan 😆. Thanks for teaching us about small engines Dan 👍

[@Diagnosedan]

Yes i might focus on 2 wheelers when i get to old to crawl under a dash😂

[@michaelreeves8164]

Excellent explanation of how the electrical system works. Knowing how it works makes for a skilled repair.

[@Diagnosedan]

Exactly!!

[@connclissmann6514]

Many thanks. I always enjoy the variety so please keep them coming. Given the high Dutch take-up of EVs, we may even see a Tesla in soon.

[@Diagnosedan]

If something interesting comes into my shop i surely film it!

[@BWGPEI]

Ah the smile on your face! As an old two-wheeled guy, this one made my day.

[@Diagnosedan]

I dont work on 2 wheelers often but i enjoyed this one. I wasnt sure about posting it because i didn't know if you guys would like to see it

[@herrkiwi3110]

Very helpful Dan, thanks so much. I'm glad you checked the kill switch as a lot of the time these can be a no start if they have a kick stand safety switch on them. Cheers

[@abdul-kabiralegbe5660]

I was wondering about the purpose and implementation of the kill switch feature. Thanks.

[@Diagnosedan]

You are right!

[@The-truth-is-valuable.]

Dan. very well done. From being in the 2-wheel trade myself - Side note: There is a minimum gap to be set between the Reluctor and the Pick-up, as when the gap is too big, the pulse-signal could also be too weak. It could happen when the metal bracket to the pick-up was bend etc. Otherwise, out of many of these online videos I saw, I think yours is just that tad higher quality than most of them.

[@Diagnosedan]

Thank you, yes you are right if the gap is to wide this will affect the signal. 👍👍👍

[@The-truth-is-valuable.]

@@Diagnosedan - And with "a Tad", I meant, a tad better than most of the best ones. Thank you for sharing your really valuable knowledge with us.

[@TheDisgruntledMechanic]

just pushing the videos out! awesome!

[@Diagnosedan]

Thank you 😊

[@repairingmaster]

Hello, Dan. I always wanted to know how the scooters generate their power. I have learned something new today thanks to you. Good fix!

[@Diagnosedan]

Thats great to hear

[@LionelWayne-je4vv]

Your video made more sense than any I've watched thank you.

[@Mr.Riffian]

I really liked this video. Not only did you prove the same approach works for scooters too but your video also helped me with exact the same problem. Dankjewel Danny 👌🏻

[@Diagnosedan]

Great to hear!

[@franglez2751]

Thank you for making this video about motorcycles, a new world to learn.

[@Diagnosedan]

Thanks!

[@greatwhitenorthcanada9600]

Damn you Dan. I spent an hour looking for the obd2 port. Then I watched the video in full. Great vidio as usual.

[@Diagnosedan]

🤣🤣👍

[@hmfernandes1]

Diagnose Dan fixed it again 👍👍👍 Cars version of Dr. House. Best channel on KZbin

[@Diagnosedan]

Wow that's for the great comment it's really appreciated

[@mangajack]

Don't be scared to offer different mechanical vids Dan....this was refreshing.

[@Diagnosedan]

I wasnt sure if you guys would like to see it

[@halleffect1]

Very good video. I've diagnosed CDI systems before and I found getting service information is the hardest part. this was very helpful. one more thing- CDI sparks are sometimes very faint, check the spark plug in low light to make sure it's not firing.

[@Diagnosedan]

There isn't alot of really good information out there or at least its not easy to find

[@Ghisisan_]

This is a very useful video since it more or less applies to all simple 1-cylinder engines in case of a crank no-start. It is good to know the chain of parts involved so one can check them one by one to find the root cause and replace that part. 😊

[@Diagnosedan]

Most scooters/ motorcycles/ atv's have a very similar system

[@nlanni]

Writing from the States and I loved the vid! Almost a classroom exercise of a simple, but complete system. Keep up the good video.

[@Diagnosedan]

Thank you

[@dustcommander100]

You took a lot of time to get those parts together and explain their functions! I misdiagnosed an ATV years ago because I didn't know what the stator voltages were supposed to be. I was pressured into doing the diagnosis, and told the owner my best guess was that the CDI box had failed, but I was wrong. It was the stator in that case, also. This was in the days before the internet existed and data could be found outside of a manufacturer's manual. That sort of diagnosing is not very enjoyable!

[@Diagnosedan]

Thats why its important to do some research before you start a diagnosis. But you are right, in my young days information was hard to find. These days you can find almost anything on the internet

[@richardharker2775]

A seemingly simple job by comparison but... Can be a problem to those with less diagnostic knowledge. Once again your diagnostic skill, fault finding and explanation still amazes me. Good video work also.

[@Diagnosedan]

Thank you very much 😊

[@Kieran46100]

Again I'm amazed Dan, that is an excellent presentation, I've learnt something new about 2-wheelers, thanks a million

[@Diagnosedan]

Glad you liked it

[@JoeCoool59]

Doing these kinds of basic electronics diagnoses is good practice.

[@Diagnosedan]

Hopefully it helps someone trying to fix their own scooter

[@andrewwturner]

That was a nice clean diagnosis. I'm surprised you didn't measure the stator resistances before removing it, just in case there was a wiring fault.

[@abdul-kabiralegbe5660]

I was wondering the same. It's always interesting to know the failure mode.

[@Diagnosedan]

There are some different stator types out there. I wanted to keep it simple

[@darioareviche5316]

Thank for the clear explanation, I new on this scooter I undertook perfectly the way that ignition works.👍

[@hermanscheerhoorn]

Thanks Dan! You showed us the basics of diagnosing without Gateways and stuff. That's what it's all about. knowledge and common sense!

[@Diagnosedan]

No gateway on this one🤣

[@970357ers]

Fixing vehicles others have failed to gives an immense sense of job satisfaction.

[@Diagnosedan]

It does and i really enjoyed this one

[@emilschw8924]

This was quite interesting, and back down to the basics without any of the fancy electronics of modern cars

[@johnmccallum8512]

Don't worry bikes are catching up especialy the larger capacity ones

[@emilschw8924]

@@johnmccallum8512 I saw the one Itchy Boots was riding the other day - electronic, adjustable suspension, the works...

[@Diagnosedan]

This was quite a simple one but there are more high end and modern ones out there

[@thetraindriver01]

Absolutely awesome Dan, loved the scooter diagnosis 👌👏👏👏👏👏👏😊

[@Diagnosedan]

I also enjoyed it

[@turbo8711]

Love anything you work on! Very informative!

[@Diagnosedan]

Thank you

[@decibelmonster4445]

It’s a long video but a really good and detailed one. So I think it’s gonna help me to get my bike fixed

[@kwakas4ever]

I LOVED the video Dan - always good to see some 2 wheel fixes! Plus, really liked you showing us less well equipped DIY types how to use more basic tools like the multimeter and test light to diagnose problems. More please!!

[@Diagnosedan]

Thanks!!!

[@BruceBoschek]

Very interesting and educational. Thanks, Dan! I always appreciate your videos.

[@Diagnosedan]

Thank you!

[@vee985]

Very nice change of pace. Good work Dan!🛵🛵

[@Diagnosedan]

Thank you

[@johnbickle4654]

This has got to be the best auto repair channel under God , Diagnose dan is the the man when it comes to explaining this stuff everything seems so simple and easy what a Great teacher 👌

[@Diagnosedan]

And scooters

[@orlanmedina3693]

never thought i was gonna see you working on a thing like that, loved it!

[@Diagnosedan]

I dont work on scooters very often but it was nice for a change

[@jizwinkle9822]

This is so awsum. I work on scooters. I've got a scooter with no spark! Now I can finally troubleshoot it like a pro.

[@Diagnosedan]

Nice! Good luck!

[@Spitfireseven]

This is a great video. You are the best mechanic. You did a great job here.

[@mikegeorge5148]

Watching your videos with great pleasure !

[@Diagnosedan]

Thank you 😊

[@paulwilliams2862]

Loved the video, always curious to see the inner workings of these!

[@Diagnosedan]

Thats great to hear

[@stationaryenginesworldwide]

Variety is the spice of life !! Great video Dan.

[@Diagnosedan]

Something different for a change!

[@HAKOUZWAWI]

I'm one of your fans I'm a mechanic i have workshop, I have a scooter for buying parts I was hopping watching you working on scooter Lol you surprised me thnks for everythings dan.

[@Diagnosedan]

Ha ha great!

[@chrissmith7655]

Hi Dan, loved the video and the theory lesson, many thanks from UK.

[@Diagnosedan]

Thank you

[@ZEROOOOOOOOOOOOOOO00]

You're a genius Dan. Two thumbs up.

[@Diagnosedan]

Thank you

[@ambitioushunter]

Issue and fix explained perfectly, as always 👍

[@Diagnosedan]

Thank you

[@richardpetker4337]

Thanks Dan. A few Honda trikes with no spark. Checking them this week. Great content as always!!!

[@Diagnosedan]

Nice!!

[@windspoint]

Another great video. Good to get back to basics

[@bartoszk4812]

Love this methodological approach 😊👍👍

[@Diagnosedan]

Thank you

[@ophirb25]

Excellent. As usual great diagnosis process with the added bonus of how a scooter ignition works. 👑👑👑

[@Diagnosedan]

Thank you

[@Gruxxan]

15:44 its a regulator/rectifier. the rectifier turns the AC to DC, the regulator ensures the voltage doesnt go above a certain limit, around 14.5V

[@Diagnosedan]

Thats right

[@geoffh2560]

as always an excellent diagnosis Dan!

[@Diagnosedan]

Thank you

[@OtisPlunk]

We fixed this one together on my lunch break in San Francisco. Glad I was able to help.

[@Diagnosedan]

Thanks for the help, sorry you had to work during your lunch break 😂

[@mattclifton6516]

Dan- Hello customer, we fixed your scooter. The invoice price for the Diagnose Dan enhanced diagnostics, parts and labor is $1250. Customer- But I only paid $1000 for the scooter when it was brand new. In all seriousness, it is nice to see that you will troubleshoot/fix anything with an engine. Great video describing the ignition components and in-depth diagnosis.

[@Diagnosedan]

I'm actually not getting paid for this job, just helping someone out😊

[@Mr-ue2ul]

Thank you Dan. Love to way you explain. I managed to sort my DC cdi no spark issue on my model aero engine using this video as reference. You are great mate

[@Diagnosedan]

Great!👌👌👌

[@MrForcat]

Brilliant explanation! Recently I worked in a go-kart with the same problem and after checking the CDI in a similar way with a multimeter, the culprit was the spark plug pipe

[@Diagnosedan]

Kart, atv,scooter, motorcycles all very similar

[@stevehayes7921]

Well done dan, great to watch as always

[@Diagnosedan]

Thank you

[@OVB_NL]

Really enjoyed the 2 wheeled content Dan - keep them coming! 🙂

[@Diagnosedan]

Glad you liked it, i wasnt sure if you guys would like to see it

[@elNenio]

I love how you diagnose.. you start with the basic of the system before start checking.. i worked on British crap JLR and i do the exact same thing..

[@Diagnosedan]

🤣🤣thanks for watching

[@Akercity01]

Great one for the youngsters Dan! Nice to see! Well done!

[@Diagnosedan]

I hope it can help some kids out working on their scooters

[@TheKeenMechanic]

Love the video Dan. I don't think you have ever done a video that hasn't been super interesting. You are my idol. More videos please💪💪💪

[@Diagnosedan]

Thank you 😊

[@Retirement_Life]

Great diagnosis, Dan! 🛵🛵🛵

[@Diagnosedan]

Thanks

[@carlocarval]

Awesome Dan just proves you're the real deal, thank you again for your videos 👍👍👍👍👍

[@Diagnosedan]

Thank you

[@GHOOGLEMALE]

Not my favourite subject, but hey - as you said Dan - its all learning so, top marks for the repair!

[@Diagnosedan]

Thanks for watching

[@mikechiodetti4482]

A simple electrical principle that can't work due to a broken part. Nice little scooter. Good one Dan!

[@Diagnosedan]

Thank you

[@andrewstones2921]

That was great Dan, a lot of us (myself included) learned basic diagnostic skills messing around with motorcycles. When I was 16 (44 years ago) I bought a moped with that exact fault. There was no CDI as it was points and condenser, and we called the stator a magneto, but it was essentially the same.. so that was my first ever diagnosis. I was lucky enough to have a multimeter.

[@Diagnosedan]

Thats where it started for most of us!

[@johnmiller9695]

A great video, only about a month to late for me. Still learned something new. Keep up the great videos.

[@Diagnosedan]

Sorry about being late again😂

[@mohamaditani451]

I always learn something, and consider myself a master tech, good video and good info as usual

[@Diagnosedan]

Thats great, thanks!

[@CALVINLNIKONT]

Thanks for the detailed explanation!

[@Diagnosedan]

Its a pleasure

[@tomthumb3085]

I’m not into scooters but the subject matter was still informative all the same. Very well explained as always. Thanks Dan.

[@Diagnosedan]

I dont work on them very often but i actually enjoyed this case

[@trytthisnowk]

great video ,well explained, thank you Dan

[@Diagnosedan]

Thank you

[@gixxercorona]

This is automotive education at is highest and simplest explanation, i work with electric / lpg forklifts and it is never been so relevant than ever when watching Dan explain electrical problem 👍🏻 🤴 pleasure to watch

[@Diagnosedan]

Thank you!

[@kevlec1947]

Nice change Dan, well done, stay safe.

[@Diagnosedan]

Thank you

[@freddielouh5323]

goodah! a primer on fixing a scooter. you never fail to amaze us.

[@Diagnosedan]

Thank you

[@mcquart]

Thanks Dan, my XL250 has no spark, Dan to the rescue again 💪

[@Diagnosedan]

🤣🤣👍

[@rosshannemann7772]

Thanks Dan , got a scooter doing just that, confirming what I had already thought thank you

[@Diagnosedan]

Now you know what to check!

[@vickenkaragozian2041]

That's awesome. I work on cars but i love motorcycles too. So this is great to learn about motorcycles and i see 120 AC on the scope, that's just amazing high voltage for a little scooter. Something i learned today. Thanks Dan.

[@Diagnosedan]

Yep its quite a high voltage indeed.

[@ismailmecano5721]

We all learn from you professor and waiting for next video « lesson » Thanks Dan

[@Diagnosedan]

Thank you

[@tassietony1226]

Well done Dan that was very informative thanks for sharing

[@Diagnosedan]

Its a pleasure!

[@thogevoll]

Loved it. Great to see you working on something else. Indeed something else "we" or I could run into.

[@Diagnosedan]

Wasnt sure if you guys would like to see this

[@RL-xb4gz]

I do like the video did one of those awhile ago watching you helped me know that I was going in the right direction.

[@Diagnosedan]

Thats great to hear

[@michaelmcdermott1877]

I'm a motorcycle mechanic, and in my experience on scooters, it's very common for the stator to fail. I usually test this first especially on Chinese and Italian scooters. Very well explained diagnosis procedures, and how the system works. Your skills would be very useful as a motorcycle technician. Maybe you should branch out😂

[@Diagnosedan]

I dont work on 2 wheelers very often, but i actually enjoyed this case alot

[@stefanos204]

knowledge is knowledge no matter the vehicle or the engine thank you

[@Diagnosedan]

You are right!

[@georgehanganu6754]

Thank you I've always wondered how the CDI works

[@Diagnosedan]

Thanks!

[@Garth2011]

Seems to be a rare failure for a motorcycle "alternator" however, this does prove that copper windings are not the same quality as they used to be. Very straight forward explanation of the charging/ignition system

[@Stambo59]

Unfortunately it's the Chinese windings that are not as good as most of the Japanese ones many of us see.

[@Diagnosedan]

Thank you

[@mmichaeldonavon]

Great explanation Dan - really enjoyed watching you as you moved forward on your diagnosis. And, I must admit that I didn't know that the Stator was called a stator due to it being stationary. :-) Thanks Dan.

[@Diagnosedan]

Now you know