Motorcycle

Motorcycle questions? Ask a mechanic.

Ask an Expert,
Get an Answer ASAP!

We have a Chinese motor cycle 125cc off road, last time used…

Customer Question
Hi we have a...

Hi we have a Chinese motor cycle 125cc off road, last time used 3 months ago started and ran good. tried to start today, no spark tried new spark plug , no spark. in pluged ignition cdi, tested voltage out of engine 116volts. checker wiring to switch with ohm meter circuit good, switch worked ok on off. ignition coil 11 ohms primary, secondary was 4 ohms, spark plug cap 1,4 ohms. does any thing look incorrect, is there away to check ignition cdi . volts to the ignition coil from cdi ,what would I expect to measure . thanks Jeff

Mechanic's Assistant: Have you checked all the fuses? Do you have a wiring diagram?

No fuses no wiring diagram cheep 2nd hand Chinese moto bike

Mechanic's Assistant: What is the model/year of your motorcycle?

In fortunately these bikes dont have model or year plates on them. wiring is , 2 wires magneto to cdi, 2 wires cdi to on off switch, 2 wires to ignition coil, lead to spark plug

Mechanic's Assistant: What year is your motorcycle?

3 wires from magneto to cdi

Mechanic's Assistant: Are you fixing your bike yourself? What have you tried so far?

Yes, no spark at plug. can you read first page , description of what I have tried and measured.

Mechanic's Assistant: Anything else you want the mechanic to know before I connect you?

Not at this point

Submitted: 7 months ago.Category: Motorcycle
Show More
Show Less
Ask Your Own Motorcycle Question
Answered in 17 minutes by:
9/28/2017
Motorcycle Mechanic: Louie, Technician replied 7 months ago
Louie
Louie, Technician
Category: Motorcycle
Satisfied Customers: 13,290
Experience: 25+ yrs. experience
Verified

Hi and welcome to JustAnswer, I’m Louie. Sorry you had to wait awhile but I’ll do my best to help.
Initially, please measure again the resistance of the ignition coil's primary and secondary.

This is an independent site and members of this online community provide information, repair tips, technical assistance as a form of paid Q & A service.

Ask Your Own Motorcycle Question
Customer reply replied 7 months ago
have quality meter now primary .4 ohm secondary 4390 ohms
Motorcycle Mechanic: Louie, Technician replied 7 months ago

Appreciate the post back of new readings.

And the "...voltage out of engine..."? ...pulsating when attempting to start?

Ask Your Own Motorcycle Question
Customer reply replied 7 months ago
wires in pluged from motor magneto 3 wires kicking over motor blue/white to green 55v, black/red to green 0v, blue/white to black/red 75v . if I could kick it harder I think I would get more volts, kicking motor over voltage rises and fall with motor rotation and kicking
Customer reply replied 7 months ago
spark plug cap has 1.5 ohms resistance, is that ok
Motorcycle Mechanic: Louie, Technician replied 7 months ago

This is significant. It would appear that 'magneto' has two (2) coils; pickup/pulser coil and exciter coil (capacitor charging).

Please measure the resistances of pairing the 3 wires:

  • blue/white to green - ___Ω;
  • black/red to green - ___Ω;
  • blue/white to black/red - ___Ω.

For the spark plug cap, the lower the better.

Ask Your Own Motorcycle Question
Customer reply replied 7 months ago
red/black to blue/white 510.9 ohms, black/red to green 379.5 ohms, blue/white to green 132.6 ohms
Motorcycle Mechanic: Louie, Technician replied 7 months ago

Based on these readings, it would appear that the green wire is the common ground.

Please measure again the voltage between the black/red to green when attempting to start.

We are to expect very low pulsating voltage.

And is there any Ω reading from this green wire to engine ground?

Ask Your Own Motorcycle Question
Customer reply replied 7 months ago
green to earth/engine .5 ohm, kicking over motor, measureing green to red/black, kick 1 o volts, kick2 50/60 volts, kick3 o volts,kick4 o volts,kick5 50/60 volts looks like loose bad connection recording different reading as kicking each time
Motorcycle Mechanic: Louie, Technician replied 7 months ago

The readings:

  • blue/white to green 55v = is good;
  • green to earth/engine .5 ohm;
  • 0.0Ω would be better;
  • green to red/black, kick 1 o volts = bad;
  • kick2 50/60 volts = bad.

Either way then 1 of the coils in the magneto is bad or intermittent.

Ask Your Own Motorcycle Question
Customer reply replied 7 months ago
ok thank Louie will take off magneto cover off tomorrow to see what I can find. Jeff
Motorcycle Mechanic: Louie, Technician replied 7 months ago

Yes please; an update then when able.

And clear pictures of the coils. Click HERE.

These pictures would then serve as common references.

Ask Your Own Motorcycle Question
Customer reply replied 7 months ago
hi Louie , removed magneto, black/red wire open circuit, replaced wire. now have 70 volts . this is from coil in magneto, other side of coil to frame. blue/white wire goes to sensor beside magneto , small raised dot on out side of magneto rotates past sensor (position sensor / spark plug firing). With every thing connected , no spark ,cannot get voltage reading to earth on blue/white wire to earth. ohm meter blue/white to earth 132.2ohms, kick over bike resistance fluctuates between 0 to 200 ohms as motor /magneto rotates, does mean sensor ok.? kill switch at cdi , switch off, circuit with ohm meter. switch run no circuit, connect cables measure 60 volts going to switch . wire starts at cdi up to off run switch back to cdi, I assume switch ok. at this point I'm thinking cdi may have failed, assuming position sensor ok. any ideas Louie , thanks Jeff
Motorcycle Mechanic: Louie, Technician replied 7 months ago

Hi again Jeff;

The 70V on the black/red would be the excitation/capacitor charging to the CDI = good.

The blue/white should produce pulsating low voltage; i.e. ~ 500mV when attempting to start.

Try (temporarily) disconnecting all other wires to/from the CDI except:

  • black/red;
  • blue/white;
  • green (or ground);
  • and the 2 wires top the ignition coil (presumably 1 wire is ground too).

If possible, post back clear pictures of the ignition coil and CDI+wires and the magneto/sensor+wires.

Ask Your Own Motorcycle Question
Was this answer helpful?
Ask Louie Your Own Question
Louie
Louie
Louie, Technician
Category: Motorcycle
Satisfied Customers: 13,290
13,290 Satisfied Customers
Experience: 25+ yrs. experience

Louie is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

I would (and have) recommend your site to others I was quite satisfied with the quality of the information received, the professional with whom I interacted, and the quick response time. Thanks, and be sure that I'll be back whenever I need a question answered in a hurry.

Stephanie PElm City, NC

used your service this weekend with "Trecers" help. thank you ,thank you, thank you. replaced an A/C fan motor. Local Auto Zone had part. $15.00 "tracer" fee and $40.00 for parts, I saved several hundreds of dollers at a shop. i will recommend you and use you in the future.

David L.Richmond, TX

9 dollars, 2 hours of my time, and I drove away. Your diagnosis was right on the mark. Thank you so much.

PhilMarysville, CA

Lurch. Thank you very much. I had real doubts about this website but your promptness of response, quick followup and to the point answer with picture was incredible.

CharlesWalnut Creek, CA

As a single woman, I really appreciate an excellent and affordable opinion.
Thank you Geordie, I will not hesitate to contact justanswer in the future!

SueCharleston, WV

Another great insight to what may be the problem. I will have my mechanic take a look at it tomorrow. Thanks again, Frank...you do indeed know your stuff.

JimCastleberry, FL

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

< Previous | Next >

Meet the Experts:

Jeff Policky

Jeff Policky

Motorcycle Mechanic

2,425 satisfied customers

Yamaha Gold, Suzuki Gold, Honda Bronze, Polaris Bronze, BRP

Louie

Louie

Technician

13,290 satisfied customers

25+ yrs. experience

TIMOTO

TIMOTO

Motorcycle Mechanic

1,233 satisfied customers

Honda registered technician, silver level award, former Kawasaki/Suzuki tech, 40+ years exp.

Andre Pilon

Andre Pilon

Motorcycle Mechanic

1,032 satisfied customers

Over 25 years experience, ICS, MMI, Owned shop for 12 years, worked tech-support for Harley Davidson

Kenny O.

Kenny O.

Motorcycle, ATV, Mules, Side by Side's Product Specialist. All Brands

619 satisfied customers

Worked for Kawasaki Motors as a Product Support Specialist (Factory Support) for 24 years

asphaltcycles

asphaltcycles

Motorcycle Mechanic

458 satisfied customers

I operate a motorcycle dealership and CCS Ducati Race team.

Glenn Adams II

Glenn Adams II

Motorcycle/ATV Technician

393 satisfied customers

6 years Motorcycle/ATV/Water Craft; 4 years auto; 18 years carpenter

< Previous | Next >

Related Motorcycle Questions
My 07 yamaha r1 doesn't wanna start it doesn't crank either
my 07 yamaha r1 doesn't wanna start it doesn't crank either it just has a buzzing sound and the cluster goes off … read more
Louie
Louie
Technician
13,290 satisfied customers
This is my first harley. Its a 2010 sportster 883Iron. It is
This is my first harley. Its a 2010 sportster 883Iron. It is fuel injected. I bought it from a kid that made his own pipes as they were ugly, i replaced them with vance and hines short/ staggered. Do … read more
Steve
Steve
I&C technician
Vocational, Technical or Trade Scho
7,086 satisfied customers
The speedo lights and indicator lights will go out at
The speedo lights and indicator lights will go out at different times and for different lenghts of time, and now the bike will lose power for short bursts, but only when the lights on the speedo are o… read more
Steve
Steve
I&C technician
Vocational, Technical or Trade Scho
7,086 satisfied customers
I have a serious problem with my Suzuki GSX 400t x 1982
Hi I have a serious problem with my Suzuki GSX 400t x 1982 (twin) It starts starts okay but.... Problems; 1. Idle rough and engine very noisy below 1400RMP – responds quickly to opening of throttle on… read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
I have the exact same problem. I have a honda fourtrax 300
I have the exact same problem. I have a honda fourtrax 300 93model. It was running and died. It blew the fuse to the ignition. I replaced fuse it started the blew again. Now I replace the fuse and cra… read more
Louie
Louie
Technician
13,290 satisfied customers
The thumb shift lever broke. How do I fix without a $350
The thumb shift lever broke. How do I fix without a $350 part ? … read more
Danny
Danny
Owner, lead mechanic
High School or GED
3,963 satisfied customers
My 2008 harley heritage classic keeps shutting down while on
my 2008 harley heritage classic keeps shutting down while on rides but it starts back up everytime right away … read more
Steve
Steve
I&C technician
Vocational, Technical or Trade Scho
7,086 satisfied customers
How do I reinstall a mirror on my can am spyder limited?
How do I reinstall a mirror on my can am spyder limited? … read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
2006 honda trx 680 no spark. tested stator and the crank
2006 honda trx 680 no spark. tested stator and the crank position sensor. installed new ecm, 12v to the coil but no signal , we are a brp dealer so no manuels or diagnostic computer. any thoughts? … read more
Louie
Louie
Technician
13,290 satisfied customers
Float bowl needle stuck open, crankcase filled with fuel.
Float bowl needle stuck open, crankcase filled with fuel. I'm working on a 2007 YZ450 where the float bowl stuck open and the crankcase ended up filling with fuel. The owner ran the bike not knowing t… read more
kwiggins29059
kwiggins29059
Associate Degree
219 satisfied customers
I would like to know I the black box takes a dump will you
Hello, I would like to know I the black box takes a dump will you get a code reading? And are they relatively easy to check and replace?… read more
Louie
Louie
Technician
13,290 satisfied customers
I have abob .an many people like me find there rear guard
I have a*****bob .an many people like me find there rear guard cracks .so i was woundering if a nightrain guard will fit an also what about seat configuration. … read more
Steve
Steve
I&C technician
Vocational, Technical or Trade Scho
7,086 satisfied customers
What is side clearance for rings on screaming eagle forged
what is side clearance for rings on screaming eagle forged piston … read more
kwiggins29059
kwiggins29059
Associate Degree
219 satisfied customers
Was changing clutch plates on my '95 Softail, now I find the
Was changing clutch plates on my '95 Softail, now I find the previous owner must have done something odd. I only have 6 steel plates and the spring plate. I pulled 8 clutch plates and didn't notice if… read more
Steve
Steve
I&C technician
Vocational, Technical or Trade Scho
7,086 satisfied customers
My 2015 Triglide won't throttle up and is there a recall on
My 2015 Triglide won't throttle up and is there a recall on this? … read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
I don't know if you remember me or not, but I have the
Dear sir,I don't know if you remember me or not, but I have the Yamaha TTR-50 that will not start. I recently purchased a donor bike. The electrical works great on it, but the engine is busted on the … read more
Louie
Louie
Technician
13,290 satisfied customers
I was started my victory cross roads yesterday but i hit the
I was started my victory cross roads yesterday but i hit the throttle while starting the bike backfired. now the bike wont start or if it does it runs for just a second and dies. ran great before yest… read more
Pete
Pete
Independent Auto Technician
Vocational, Technical or Trade Scho
138 satisfied customers
Just happend today, Yes, Im working on a 06 Suzuki sv650
JA: I'll do all I can to help. How long have you been dealing with this? Customer: Just happend today JA: Do you plan on doing the work yourself? Customer: Yes JA: Anything else we should know to help… read more
Louie
Louie
Technician
13,290 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x