The Ultimate GY6 Starter & Ignition Troubleshooting Tutorial 

This is a Fantastic Video , As a 67 year old retired Technician it is rare to find someone Mature enough and smart enough to help others in a professional way . Countless baby brains only want someone to view their ignorance, but this young man is beyond words as a good Samaritan . The Video is excellent, detailed and extremely informative . Many Americans bought these CHEAP scooters on line and wound up parking them , covering them with a Tarp and left them to rot . Cheap Chinese junk , kind of like the old GM built Cars . So I viewed the video a couple of times , pulled off the Tarp of the Gy6 machine that had been parked for 5 years, found the problem in about 30 Min , Verified the problem and found parts online . It was extremely difficult to find good publications or technical help . The Chinese companies could care less, they basically disappeared once the sale is made . Thanks to Caring people like this young man whom not only is very intelligent , and very patient , he is very caring . He is helping thousands of Americans and others across the World . By the way, Texas offers Free education and jobs of making 125,000 per year , as a Technician, come down to Texas get a Free 2 year education , an associates degree and have above 90% chance of being hired before graduation . Countless Downstream Technology jobs await those that are smart . Learn the difference between Upstream, Midstream, and Downstream Technologies,

Thank you for the video. I have been taken advantage of by so called mechanics to the point that now I have no choice but to try to diagnose & repair moped myself.

Thank you for the excellent trouble shooting guide. I just bought a gy6 49cc with no start. The engine would spin with the start switch but no spark. Followed your guide to the tee and still no spark. So I pulled the front cover off and found that someone had installed an alarm/remote start. Removed the alarm and shorted the pink and black wires. Then traced the kill switch wires all the way to the CDI. Still there was a persistent ground on the kill switch wire. Found that this bike has a kick stand switch. It was shorted all the time. Once I unplugged the kick stand switch I had spark and the engine runs great now. The point is I was able to follow your guide and determined that the CDI, Coil, and Stator pulse generator were all functioning. And because you included the kill switch trouble shooting I was able to find the problem. Thank you!!!

Thanks man, my coil was bad this is an excellent tutorial on how to troubleshoot electric problems,scoot runing again thanks

Now this is an excellent, thorough troubleshooting tutorial. Bravo sir, I have been wondering how to check the kill switch without tearing the steering column apart. Well done

Thank you for this. I scored a cheap scooter and your video helped me trace the problem to a bad kickstand switch that was keeping the black wire grounded.

@tiehut In this world we have many good people, but unfortunately there are also many "Losers" as you stated. I prefer to call them trolls. There is no reason to thumbs down this video. I have seen many videos on RU-vid, and I can say that this video is EXTREMELY helpful. If an individual did not think it was special, then just move on. There was no reason for the thumbs down. Some videos are deserving of a thumbs down, but not this one. I suspect the thumbs down are from viewers who could not resolve their issue after watching my video because either they failed to do something correctly, or they have other problems not shown in this video. So I get blamed. Illogical considering they did not even pay for the help I gave.

Thanks for this video bro, all the attention to the CDI helped me locate my problem. For others out there, my scooter wouldn't start simply because one of the wires to the CDI Controller had come loose, plugged it back in, rigged it up with electrical tape, adjusted the idle once she started up and all was good, took me three weeks to figure that out until i saw this thanks again

i have a jonway yy150t-12. I am glad I found this video because it is basically the same as your bike. I just had an issue with a bolt not being on my manifold. The other one started to come loose as well so it was dieing all of a sudden when i hit the gas. Had serious issues trying to get a decent idle RPM. Seems to be doing better at the moment. Thanks.

Wow this is by far the best video step by step as far as running down any electrical problems. I myself know a little but with the help I've seen here I'm sure I can get this scooter running if my problem is electrical, which I hope it is. Got the 150 cc sunl scooter for $50 I know I will be putting some money and time into it and watching more of his videos. Just want to say thank you so much for taking the time to do this for people like me.

Thx for video.. Just wanted to mention some scooters have a kill switch activated by the kickstand. Not allowing spark if the kickstand is in the out position. Found this out the hard way..Denny

Do you are very awesome I can understand you you're not too quick very therrell you're a good teacher I thought I knew a whole lot about electric you're really helping me out I never really paid a lot of tension the multimeters but it really helps thank you so much you got my vote Steve from Annapolis they call me Super 6 GY6 most of the mechanical engine stopped them a pro at

I am waiting for my scooter to arrive I just ordered a few days ago I have been watching videos constantly since then and I must say yours are incredible I look forward to everything you upload. I am ignorant when it comes to anything electrical or engine wise I have never been involved in dealing with either or either end in buying a scooter that did not come highly recommended I knew and understood I would have to learn some things or pay 4 things and in my situation learning is better even at 47 so I just wanted to thank you because I think that your video will probably be the most useful item in my arsenal of keeping this thing going I ordered a couple of books off Amazon used for a few bucks as references but once again I commend you and being so professional and explaining everything from soup to nuts in your video hopefully I will not have to use it very often but if it does not start your video will be the first one I go to again thank you very much

I've got a yy-150 that doesn't crank and doesn't turn over with the ignition. Not mechanically minded, but I've already replaced the battery, cleaned the carb and replaced the spark plug. No idea what it could be at this point, but thanks for having this up. I'll watch it a lot for sure.

Great tutorial so far. Car / Semi mechanic here so alot is familiar with the few exceptions. Still watching video. At Appx 5:45 in video you show a "Scotch Block" on the back where you ran your ground over. Recommend eliminating scotch block as that invites Gremlins (Corrosion) in the wiring. Better of cutting small section of wire, stripping the end of ground wire you're adding and twist it in the wiring inline then soldering it. You can use liquid tape to put a cover back over wiring sealing it. I generally go 2-3 coats of liquid tape. I do this on any similar wiring situations, remote starts, wires I may pierce with a test light for diagnostics and it don't hurt the current wiring. Now off to watch rest of video. Good battery, scooter starts, runs when kickstarted, runs when battery charged but the starter goes but sounds like it starts spinning before I have to pull the battery and charge. Wondering if alternator or whatever these have is going bad. I do have a voltage drop tester (see AESWAVE.COM as they have alot of great mechanic tools that help save time and get sale result). These tools are great when you do alot of this stuff as it pays back long term. So far scooters are cars on a smaller scale. Loving it. May start doing work on these as well. Wonder what a good hourly rate is for scooters?

Very very helpful. Thanks for taking the time to do this.

Best video I have seen yet. I am working on a Buggy with a gy6 engine that had been setting for years, I need to trouble shoot all the electrical systems. This video will help immensely. Any place to get the simple wiring diagrams that you are using. Most of the time they are very complicated.

Great video but just one question. What is the voltage reading from the CDI to the coil primary? Thanks again for the great video.

Thanks dude , very elaborate professional ,educational video

omg, why i have no friends like u :) i find smart ppl only out of my country. This is so exact what i need, i still dont believe what i have found. i have subscribed to u because an other video of yours, but this is like i hit gold :D. TANK U ! u r really smart

Absolutely Brilliant, best description of any troubleshooting i have seen. Really appreciated.

Incredibly good video! Very thorough and educational.

You really covered things well in this video!

Thanks a lot very helpful we had problems with our scooter not cranking fast enough after watching your video we found the ground wire on the frame came loose thanks again very very helpful

it was good to have first saying the name of the parts and then showing them. that makes understanding better.. good video

Be sure the kickstand is all the way up. My wife's scooter had no spark. Was in the process of diagnosing the electric when I saw a reference to kickstand in one of comments. Pushed it down and back up. Coil began firing. reconnected plug wire, started instantly.

Great video thanks for posting, it's been a great help on a scooter project for me and my boys. God Bless

I like these types of videos so thank you...while I'm here I have an oil leak on my Geely 150cc JLT-30. Parts here are hard to come by as well as mechanics so I gotta do this myself. I understand these are GY6 engines so wondering if you ever did a video on oil leaks and repairs, remember parts replacements are rare for this particular scooter. Anyway thanks for the vids!

Hello, and thanks for the great video up front : ) I hope you are still open to a question or 2.. I would like you to know that i watched your video several times over by the end, and tried to listened very carefully before posting any comments / questions, as to not waste any of your time. Hopefully i did not miss anything i am about to ask ; ) Just a couple bits of info first that may help. This is a go kart with the gy6 150cc engine. I have no keyed ignition (push button). I just tied the on / off switch wires together for the tests just to rule it out of the equation all together. Switch tests fine though. There is a secondary safety switch on the brake pedal. The starter will not kick when you push the starter button unless you are holding the brake at the same time. That switch is also functioning fine. My 4 pr. wire harness going into the CDI only has 3 wires in it. I Did a continuity test of each wire. 2 of the wires go to each lead of the coil,(if 1 of those is a ground then any ground would show continuity i guess) and the 3rd wire is the pick up wire. Other than those couple things, some wire color differences, and the fact that the fuel gravity feeds on mine, everything in your video matches what i have here.. Moving on... @14:00 mins. of the video i guess is a good start. Coil OHM resistance at CDI. I am getting an OHM measurement of .8 -1.0 for this test. (tester set @200 ohm) I have 2 coils, both are used, and they test identical for all tests moving forward... I am getting that .8 reading no matter if i test through the wire that goes from CDI to the coil, or if I just test directly to the coil. both coil wires at the CDI read the same. ( i also get the same readings if i just meter the leads on the coil directly while not connected to system) Skipping forward to 19:30, Coil tests. I did this test exactly as you recommended. With boot / wire off, black meter lead to green coil lead, and red meter lead directly to the screw inside coil (meter set @20k OHM)it reads 3.24, Boot / wire back on. Black meter lead still connected to the green coil lead, and red meter lead to the end of the spark plug wire, same setting on the meter. I get a reading of 8.9. Do you see a problem with any of my readings. By your readings at 14:00, my readings are pretty low. although i saw your caption there as well...)Is my coil ok? All the other tests that i went through with you on the video seem to be with in the same operating specs.. I am stumped! Still No spark! A new spark plug is next on the list as soon as the store opens. I will cry if that's all it is. I usually just have them around, and never hesitate to try a new plug first. I followed the spark plug test portion of your video, first time i have tried this, but that was not looking good for 2 plugs i have. 1 of them has no continuity between the tip and the electrode (junk), and the other measures with higher, and erratic resistance measurements, so it may be bad also. If not that though, what do you think? Would you still lean towards the CDI unit? I would really appreciate any time and info you would be willing to share. I learned a ton from your video, and i would like to thank you again for that.. The title does not disappoint! I hope my question & info is just as clear. Thanks in advance. -EJ

Awesome video, awesome detail. Watched it over and over a few times. My problem was my ground terminal came off while cranking over the engine and it idling. The scooter shut off, I placed the wire back on, went to fire it up and nothing. Going to try this tonight when im off work and see what the problem is.

good vid very informative, and not least very helpful. Thanks guys

I never heard about this brand, but thanks for share your aconoledge .

3:37 I am talking replacing that exact petcock vacuum valve with a manual cut off switch fuel valve.

Can't thank you enough, replaced 139QMB with 152QMI & there was a slight wiring difference but thanks to this video alls good, thanks again :-D

This video kicks ass - thanks for your video.

my dude shortly after running harness through frame no spark ended up bad cdi very helpful

Thanks a lot that should help solve my problem appreciate all the time you put into it.

Thanks for the video. I have a problem with my scooter. In cold weather especially the electric start just overruns, doesn't crank (make the tatata sound). Kick starting usually will start it but yesterday that was not the case yesterday. Kick starting is not good for my previously broken ankle either. Anyway, the shop can't seem to fix it so I'm trying to. Very helpful and well done video. Thanks again

This is one of the few EXCELLENT trouble shooting videos that I have seen on RU-vid. I wish the author creates a similar one for another Chinese scooter - Valentine (marketed by Puma) 150cc Model 150T-c If anyone knows about trouble shooting electrical system for this model, I would love to hear from you. Thanks!!

Very good video for gy6 important & relevant factors

Thanks man!. I couldnt get my gy6 scooter running after transporting it 500 miles in a trailer. No spark at the plug. i swapped the plug, coil, cdi. I was checking craigslist for a person that knew what they were doing. I wasnt having any luck in my area. THEN, I thought of u-tube. yours was the first one I clicked on. I was wondering why you wouldnt use a test light or meter to check the starter solinoid. I fast forwarded to the 6:45 point and paused the video..........when I got to the kill switch part. I went outside and put the switch in the correct position, and it started! Thanks Again.

wow Im hoping this can help me get my Jonway 150 cc running. It has less then 500 miles & just wouldnt start 1 day.iM NOT LOOKING FORWARD TO HAVING TO WORK ON IT MYSELF...SIGHHHH You are the best!

my friend gave me a 150 that wouldnt start when i watched your video about the kill switch, ill be dang i went outside and the switch was on kill. that is the first scooter ive had so thank you for your informative video

2021 and this is still a very useful well presented video. Thank you.

Amazing video. Thank you so much

Ok I did exactly the way you said in the video and it was very helpful,I think I may have found the problem in the starter,when I bought this bike from a auction,as I am now taking off the starter the starter wasnt bolted down to the engine,it was just in there,when I gave it a few taps it just pop right out of the gears,does that mean anything? Like just stuck in there but locked into the gears?

Do I have to have a coil installed for the lights to be able to come on and the engine to turn over? I picked up this freebie 2011 TAIZHOU ZHONGNRNG 50cc that is totally dead. My ignition switch is busted so I twisted the black and red ignition wires together until I can get another one, twisted the two green wires together, ( left the black/white kill wire disconnected), I am able to turn the engine over by jumping the solenoid posts, battery and fuse are good, start switch and brake switches tested good, there is continuity on all wires having to do with the starting system yet the lights will not even come on. What am I missing after following your tutorial.

thank you so much for such a helpful info. great way to explain things. my question is about the green wires. you only refer to one. why do you leave one out? thank you so much, before hand for your answer

Great job.I really enjoyed this .

Great video! It was very helpful while I was troubleshooting my daughter's Schwinn hope 50 scoot. As it turned out, I had forgotten about the kickstand-kill switch on this model. >face-palm

Hi there! What a detailed video! Have a question for you. What if my starter makes a sound like it's not engaging to the engine? Like when I git the start button, it's sounds like it's working but just not engaging. Please help?

If you get readings close to the values shown in the video, then it makes no difference how rusted.

Hopefully I can figure out what’s going on with one of my ATVs from this guide GY6 is a great engine until it doesn’t want to start

Thank you for all the detail and info. You're a helpful & thorough guide. I pulled the wires from my cdi while hoisting my scooter into a pickup bed. I think I can figure the correct placement for each wire but one got cut and now is difficult to get in and get to stay in the plug. Do local hardware stores carry this small of a connector usable to plug the wire back into the cdi box? Your help would be much obliged.

I've gotten in trouble with ohm testing before since the DMM itself supplies a very negligible amount of current. Partially open/shorted wires have passed the ohm test because the trickle of current coming from the DMM found it's way through just 1 or 2 strains of copper in a wire that was otherwise damaged (mostly shorted/open) . Voltage drop tests may be a better solution. OHM tests can often lie to you or not tell you enough. I think a voltage drop test on a LOADED circuit leaves little to no chance of a false positives.

Great video, good to see someone make a proper video instead of some ghetto person holding a shaky cam yelling about random things while the dogs bark in the background.

Great Video. Very helpful. My starter coil did not have the screw you were talking about so couldn't do that part of the test. My ohm reading from ground to the coil was only like .8 so I'm guessing it's a bad starter coil?

Very useful Bro 👌 🎉🎉🎉🎉

Great video! My Chinese scooter ignition coil reads approx 0.4 ohms directly across the terminals (shorting the dmm leads is 0.1 ohm) , the bike doesn't crank. Could my ignition coil be a little different from yours, that reads approx 2.0 ohm, but is still good?

Great video, I followed it step by step after watching many times. Everything checks out with my scooter except the stator is putting out about 50 VAC, not higher like you mentioned. Could that be a low enough voltage to cause the no-spark, or is it more likely the CDI is bad? Thanks again.

Thanks for the help sir

Thank you 👍

Thanks to this video got my moped going,

First off I have to say u sir electronicsNmore are a genius this is an excellent video and is very informative. I have a issue which with my scooter. It ran the day I purchased it and haven't touched since then. Stored it till all paper work was done, about month and a 1/2 later doesn't want start. Is this due to bad gas, switch in brake or kill switch this is just what i figure. Your help would be graciously appreciated and any other of you guys out there.

Hi there. I will bust my meter out tomorrow and check a little closer as you show, checking the wire from the kill switch. I have already installed a new cdi box and the solenoid, battery is charged. When i try to start, lucky if i even hear it try to kick over. For the most part I just hear the solenoid clicking. A few months back, it would start sometimes, other times not. Do you think I should try new ignition coil and/stator coil, perhaps the starter? I followed this long ago having similar starting problems, and just ordered 3 of those components(cdi, solenoid, ignition coil), put them in, fired right up. My scoot has about 7500 miles on it. Have not really changed anything aside from what I mentioned above. 2012 evo 150, same color as yours actually. Thanks, Doug

Excellent Video and I learned much. On my Schwinn Graduate, I got no readings from the coil, leading me to believe the coil is dead. I knew I had no fire by using a simple inline spark light. Now I just have to figure out where to buy parts. Any suggestions?

I think your work is really helpful! Thank you very much. Does anyone know how to test a non-mechanical speedo cable setup? Please? Remember, its a magnetic impulse type speedo which isn't working. When it started breaking down, it seemed to work intermittently, flicking on and off. Cheers, Den, Wales.!

great video, when measuring my resistance from the black and yellow wire it was high. you mentioned not above 3 and i got 5 . any suggestions on my next move?

very nice video that can help dig. scooter, motorcycle & 4 stroke outboard.....

I’ve been schooled, thank you

IMPORTANT!! When testing the green ground wire going to the CDI, does the key have to be on or off?????

ElectronicsNmore, thankyou for taking the time to create the video.I have confirmed my kill switch is not working as intended by carrying out the first test (i.e. always off regardless of switch position).I do have a question: Will the readings for the remaining test be affected by the kill switch not working?The reason I ask is I'm getting inconsistent readings, numerals flickers erratically upon contact of the prongs and immediately zeros out.I have bridged the handle kill switch cable but i believe the issue to be in the ignition kill switch unless my entire wiring harness needs replacing.note I haven't use a multimeter since high school.Thanks in advance.RegardsSergio

very good video. Mine GY6 is not cranking. Only when I jump the solenoid? You can make a video about that too

Great video, I went outside to start my 50cc,,,, hit the start button and nothing,,no cranking sound, battery is good, brake light and horns work, if I probe the soloniod with a test light hooked to batt neg, it lights up, if I use a screwdriver to short the starter soloniod it cranks the bike, it wont start because its having a spark issue, I think its the right side kill - start button switch, issue,,,what do you think at this point? TY

Just curious is the idle enriched an open or closed loop component? Also do you need neutral switch to get spark?

THUMBS UP... GOOD VID..... THANKS..

Your videos are helpful. I put a new motor on my 150cc vento 08 and it don't turn over. I used a tester that just lights up when it's on the plugs, i changed the back wires and cdi box still no start. If it's the alarm that won't let it start what do i do?

Can you kick start it?

Excellent video - thanks! So I have a Chinese scooter (never again) and my new battery (2nd) is not holding a charge; I checked the stator wires and they appear to push energy... what do you think I should check? Thanks again

Great videos! So good I had to subscribe. I am having some starting issues and my scooter has an alarm, how can I remove it or at least find out if it isn't causing my hard starting issue?

What your thought on checking coil having the voltage being solid not pulsing? Ultimately i don't have spark that is the starting issue at this point. Thanks again. My scooter does have auto start on the key foband i am wondering if the alarm has a kill switch not letting the spark.

Good video, I have a question regarding the "load:" you have represented across your two leads on the four pin connector. I'm new to scooter troubleshooting, but the cdi, on ac units, shows 2 parallel circuits, one for the coil that feeds the spark plug, the other lead feeds the pick up on your stator. The way you show the load in the video is only across a coil?? Is your circuit correct? Or is there 2 parallet circuits as described above. Thanks for the info.

Hello electronicsNmore,love your videos man. So i have gy6 125 cc scooter.And it has no spark.I check cdi,stator and ignition coil, everything is alright,but when i check kill switch with it being on it always shows me that it's grounded,and i dont know if the problem is with kill switch or key switch,how do i find out,whith which one is the problem? Sorry for my bad english.It's not my native language.

I just have a random question .. On the 4-plug part of the CDI .. What was the reason behind them making it 4-Plugged if many of our scoots only have 3 wires?

When checking the green ground wire going to the CDI does the key need to be in the on position? ???

Great video, on the one i'm working on all I did was replace the drive belt. I did turn engine beckwards some. But now it wont start, it has spark and fuel. When you take plug wire off it sounds different than with it on.I also replaced plug still no start.

Thanks mate. It just strange that it only done around 1000kms. Do you have a video on how to adjust valves?

Video is really good. I have just bought a vmoto milan 50jx. Its not turning over, ie startmotor gets nothing. Bike was initially stolen and I bought it after. I hear a clicking noise coming from the solenoid when I start ignition. Any ideas?

Great vid. My cdi, coil seems fine or I have replaced. I have good spark but the scoot won't start even with starting fluid HELP

This and you are AMAZING.

Great video tutorials,I have a problem where the engine want turn over period its just frozen, the electric and everything works but when I try to start it the motor want do anything,could that be the starter?or should I check and how do I test to see if the starter is good?thanks for any suggestions>

I need to replace the ignition coil, do you sell parts.

Some scooters have a kill switch connected to the side kick-stand to prevent starting with both wheels on the ground and no rider. The starter motor will still turn over but the switch will not provide spark to the plug. Easy to overlook this safety feature.

i have an old parts scooter that i took the engine from for a used vip i had to change the mount, now the starter won't engage the flywheel any ideas? it did work 2 years ago when i parked it

Hi I’m having a major issue with my gy6 scooter basically when I’m getting no spark and I changed out the whole entire ignition system and even knew battery and still not getting a spark I changed out the cdi and ignition coil and new spark plug and when I turn the key there’s about 3 different wires that start to smoke and get hot what can this problem be and how would I fix it PLEASE leave some advise and I love ur videos man??

My problem is with fuel delivery. The scooter (Lexmoto still chinese rubbish..) is using up what fuel has dribbled into the carb then cutting out and not starting until more fuel has entered. Can I simply replace the pain in the bleeeep vacuum fuel petcock with a manual cut off switch with no vacuum? Save me so much hastle replacing all those horrible cheap hoses. Just will replace the hoses that are being used i.e. fuel lines. Seems like so many people online have I think you mentioned your manual cut off switch you installed in another video? They say "cap off" the vacuum line that goes into the vacuum petcock and it should be good to go.

well done.

what sort of resistance reading should you get on the center electrode with a RESISTOR type of plug ?

HI, very helpful video, good job! My scooter won't start no spark all of sudden. Followed your video when I test the red wire coming from the stator, no resistance reading and no current coming out of it when I crank the engine. What does it mean, is my stator bad and needs to be replaced? Please reply asap. need to fix my scooter. I use it for work. Thanks

thank you very helpfull