Ignition system testing, Magneto coils, Points and CDI 

Pretty much, since it is dependent on the windings from the factory's spec.

it dont mean any thing with a manual only that it not open that coil is nothing but a lenght of copper wire wrap around a piece on iron so as you apply a voltage it magntizes that iron the secondery winding is wrapped around that same iron so the magnetizem creates a high voltage inthe secdonary winding which go to distribtor and the `spark plug so there is not a lot to see with the ohmmeter

Just bought a KE100 Kawasaki - no spark. Will test the coil tonight.

This system is very similar to almost every breaker point ignition.

+Timothy Peters thanks

Flubbed my lines and the wife behind the camera noticed it.

♥️♥️♥️♥️♥️🔥🔥🔥🔥🔥😍😍😍😍🌄🌄🌄💋💋💋💋💋💋♨️♨️♨️🌄🇳🇵🇳🇵🇳🇵🇳🇵🇳🇵

You might or you might not. Adding a light bulb in the system ads more resistance that the coils are not designed for. I know what you are thinking and it would be an inconclusive test. This is why the manual's state to test the resistance of the coils to determine if they are good/bad.

That's not the best way, the best is with amp clamps and oscilloscope amp curves under load

+Lozz Mitchell I could and might however its kinda futile as the condenser is cheap and easy to replace, and you have to remove it any ways to test it.

I use this for demonstration purposes only but yes to use this Magneto and stator plate I would have to replace the coils by simply unsoldering them and soldering the new ones in

It means the wires are degraded and causing higher resistance.

Given the vagueness of "magneto and cdi off ebay" I would probably say no, unless it states it will physically fit on your machine.

I am not sure I understand as the condenser connects with a fork connector to the points. Its only job is to briefly store energy ,that is induced from the coils, to jump the points when they begin to open, which fires the plug.

thejunkman My condenser has 3 wires soldered on. On on side of the fork the wire from the excited coil and the black output lead, the other side of the fork has the wire to the points soldered on. I have been told that I can join these wires and solder to the top of the condenser

Sounds like you can.

+Eric Hess check your magneto cold resistance per the manual. They are probably near the limits.

+romulo parrilla no, the neutral light has nothing to do with it. Test all the coils. I have those values on my website.

I am not sure what you mean you converted the stator to "battery operated" the stator is what gets its current induced via the spinning magnets.

Voltage reg pretty much just regulates the voltage

Yes, it is an odd pattern. I have a really old Motion Pro universal puller that has holes that fit this pattern (among other patterns) but it is not made anymore that I can tell. This one looks close, but have no experience with it specifically. www.amazon.com/Universal-Motorcycle-Flywheel-Puller-Suzuki/dp/B005SUUB6K I have used other "Pit Posse" branded tools/pullers with success so the quality I have experience is decent. You can make your own out of plate steel and some bolts. A 2 bolt puller will work using only 2 of the 4 holes, just have to be patient and some persuasion to bust it loose. Using only 2 bolts will risk stripping the threads as the load is only spread over 2 rather than 4 bolts. If you strip it is not the biggest deal as you can drill and tap to a larger size if needed. Hope some of this helps.

@@thejunkman Thanks. Thought of making one. Also looked at the 2 bolt puller. You think the 2 bolt timing gear/steering wheel puller will work? That Pit Poose might work too.

It might, as long as it is slotted so the distance between bolts is not fixed.

Ebay, saved search.

No. Oil will not effect operation.

Great! Then I did my job well.

Did you watch the video? It shows you some ways to diagnose the problem.

You can't. Yoy will have to follow the wires, or read your service manual and it will tell you.

@@thejunkman ok thanks, and one last question how figure it out if the coil is damage by looking at it?

You can't, you need to test it like I did in the video. This will require the manual for the specs.

Yes. It is how the field coils get current induced into them.

Your service manual will outline the procedure and specifications specific to your bike for testing. Sounds like you have a CDI equipped bike which the testing is the same, just have to know what the ohm readings should be. If you need more help, post a picture to the comments on my website. Link in the description.

I don't have a service manual.Have a look i've send some photos on your website....thank you

Yes, which ever one goes to the points on this style of ignition or the one that then goes to the CDI box.

thejunkman thanks man! I have a Honda atc Big Red that fouls spark plugs regularly. At first I thought it was the carburetor but now I think it is from a weak spark. Have you ever seen a bike that had spark and would run but the weak spark wouldn’t let all the fuel burn?

Yes, and usually it is a mag coil problem or a point problem.

thejunkman ok thanks again! I will check it out.

By your test result yes, the resistance is too high.

@@thejunkman Thank you so much! Just for experimentation sake, I unwound the wire from the coil. I tested the end to end resistance and it was about 2.7 OHM (the same as when loaded on the bike/assembly). I then cut off wire until I reached an end to end value of 1.6 ohm and it took removing approx. 25 or 30 feet to get there. The remaining wire is about 50 feet long and produces 1.6 ohm. I don't know what this means, really but I thought you might appreciate the information.

+aftab malvi I would use some dielectric grease on all connector. That will help with you water problem. The drivability problem is jetting related. I have a video on that

thejunkman you mean inside the coil assembly?

+aftab malvi no the electrical connectors

I would need one for demonstration. But a manual and the basics shown here will help

This post is very hard to read. I am not sure your question or what your trying to communicate. I understand your battery is draining, but that is about it. With the bike off put a volt/amp meter between the positive terminal and positive lead and see if there is any current draw with the key off.

@@thejunkman how.to.set.dkw.points.3.cyl

There is really not a good test for those. Replacement is the best option because they are cheap. First check for grounding issues though

Ritesh Singh Rathore He explains it in the video, The 12v coil will be always be larger in size because it has more copper wire wound around it than the 6v does. If your bike has 6v lights and 12v ignition the smaller is your lighting coil.

Go here www.thejunkmanadv.com/repair-and-service-manuals.html Scroll to the "Typical Honda/Chinese Clone CDI wiring" Ignore the color coding but it tells you which wire and connector goes where.

thank you!

Heat? Yeah probably. Grab a manual and test your coils. www.thejunkmanadv.com/repair-and-service-manuals.html You can purchase a manual using an affiliate link, helps me keep making videos.

+Tom B i am not aware of a test for it

So is it the case that the CDI firing sensor just gets bolted into place near the flywheel, and that's the end if it? No adjustment?

+Tom B no, it is not adjustable

Thanks Junkman! Keep up the good videos !

The flywheel contains magnets that pass by the coils of wire wrapped around an iron core. The magnets induce current into the coils, the current is then briefly stored in a capacitor and then that current is released to the primary windings of the high tension coil to then be induced into the secondary coil, stepping up the voltage strong enough to jump the spark plug gap to reach the ground.

No. Your problem us jetting. It could be a rich condition for some reason.

thejunkman thing is the riding mower just up and died while mowing along with no symptoms except the occasional backfire some days. will not start or fire at all other than a backfire and flame out the carb. if it’s got fuel compression and spark shouldn’t it have some ignition at all? valves are fine, very slight leak which I just lapped the valves to correct but nothing enough to cause this. even rich the gas should ignite some in the power stroke i’d think

That is the thing, it is igniting the fuel and spitting it out the carburetor. I guess it still could be a magneto coil problem not firing all the time under compression. Usually those motors don't have a spec to check like indicated in the video.

Not familiar with that term

thejunkman ..sir...i mean four stroke bikes have timing trigger rigdes on outer side of flywheel...but they differ in legth ....some are small...some are long...why??

I would have to see a picture of what you are talking about. Post one to my website in the comments.

thejunkman ok sir...thanks

Are you following the procedure outlined in the Polaris manual? That second to last sentence might be where your trouble is, however I don't understand what you mean.

Thanks for the reply man!!! I test the ignition coil tab and get good reading. I test the coils ground and I don't get, .05 I get a higher reading. So, what do I do to get a proper group reading? I cleaned up battery, solenoid, and ground cable going from engine to frame. I don't know what else to do. Unless new ignition coil is actually bad. (it's happened to me before with new parts).

yes I am following procedures. To the T

Well if you can't get the ohm reading from the "new" coil, per the manuals instructions, then I would say you have a defective part. I am not intimately familiar with your quad so I have to assume you are testing it correctly.

I'm very grateful for the reply man!!! I've been stuck on this for a while. I'm testing correctly as far as I can tell. Ground from coil to one test lead, other lead to engine case. I just don't know what else to do to get a proper ground reading other than change the coil. So, I ordered a new coil, and also a used "working " one from eBay. All I can do is try them at this point I'd guess. I'm a machinist /millrite for 26 years, no electriction lol

Lol, ok.

Replace the head gasket first before trying to diagnose any other problems. The rest of your sentence doesn't make sense.

i know its leaking oil from the premix. i will replace the head gasket first thank you.

Kevin Stearns Let me know how that works out.

i will

i replaced the head and base gasket and the sob still backfires.

I am assuming you mean you have a CT70. The Honda factory and the Clymer manual list 1.3k ohm for the primary coil. Typical range can be +/- 10% of this value. This must be tested with the breaker points open and the condenser wire un-hooked or you will get an in-conclusive value. Also your symptom could be a failing condenser, since you will have the flywheel off to do the other test, you might as well replace it and it is not a bad idea to replace the breaker points themselves as the contacts might be worn. You can perform a test on the ignition (spark plug) coil as well. Primary coil resistance 2.1-2.3 ohm (black wire to ground) & Secondary (high tension wire to ground) coil 9-11k ohm. However this test can sometimes be in-conclusive as the secondary coil is highly dependent on the primary coil. All these can contribute to a weak performance at the plug. You may want to check out CHP (classic honda parts) they have a lot of this stuff brand new, or suitable clone replacement parts.

@@thejunkman I have a 1980 C70 Honda motor bike, AKA a Cub70, or Passpor 70

@@thejunkman I have replaced all other components including diode, ig. Coil, condenser, plug, confirmed cut off at ig. Switch and kill switch.

@@thomaspencak5811 Ok, well they are the same engine either way.

@@thomaspencak5811 Then test the primary coil (under the flywheel), that is probably the culprit.

I have no idea

Burning the coils? I am not sure what you are asking. Coils can fail for a number of reasons, most commonly is the degradation of the insulation between the core and the wires (winding). This material degrades from age and vibration over time, especially in 40+ year old bikes.

thx for your respond. by burning i mean, the coils where melt down (2 of 8 if im not mistaken) and they where black, like they where overheated.

Thanks. Be sure to check out other videos and my website for more information on this topic.

Because that is how the test is done per the procedure in manual. Nearly all coils in magneto ignitions are tested this way, irregardless of bike make/model. The spec or range of a "good" coil will be different (obviously) for a different model of bike, but tested just the same. All that is happening here, and this is explained in the video, is magnets in the flywheel are inducing current into the coils as they spin around them. Improper resistance within the coils by a break in the wire, degradation of the insulation between the wires and core will cause a change in this resistance and thus induction will not occur.

some of these bikes don't use DC voltage, they Pruduce AC voltage.

I have no idea what a code number 76 is. It has diagnostic codes? Never heard of that in scooters. I would check the service manual and see what it has to say.

@@thejunkman Thank you ... I would be thankful .. Waiting for your reply

No, you check your service manual that you bought for the bike. We don't have access to this model here in the USA.

@@thejunkman Thank you

Start by replacing the points and condenser if you haven't already. Then proceed to test the coils resistance per the manual .

@@thejunkman Is the Clymer manual good?

Also need to verify what year mine is. The VIN on the head tube is MC-507593. Do you have a way to verify year and model?

Yes, it is nearly identical to the factory manual, except it has more pictures and more explanation and the grammar is better. Buy one here if you like. tinyurl.com/mc1manual

It is a 1974 MC1M

In short, yes. The a "good" coil will be within 10% of the stated value (.5 ohm). Too far on either end of that 10% range means it is just on the fringe of being about to successfully induce a charge from the magnets whizzing by the coil.

thanks JUNKMAN!!

@@thejunkman so I just bought a supposedly "NOS" Primary coil part number 21049-013 on ebay and it is reading 1.5 ohms across the two leads (not installed yet). I am interpreting your comment that it should be reading 0.5 ohms so it is not a good part, right? I also get 1.5 ohms when I measure across the original Primary coil leads.

Good video but the test leads could well be 0.2 ohms each so short the leads and remove that number from the test results Also the wire to the coil may or may not be includes in published results I think we can say that coil could well be OK Maybe cleaning the coil earth connection could well lower the resistance a bit . I do not think the coil itself is going to be at fault if it is only fractionally above the spec. If it was low then yes it could have shorted turns

Yeah, means a magnet is loose.

The ignition coil is probably "ok" as it is really hard to get an accurate reading on the primary winding because it is also dependent on the secondary. Your problem is with the magneto coils as they test out of spec. Basically all the "energy" is generated via induction into those coils first so if they don't test in spec then it really doesn't matter if the ignition coil does or not.

Usually just 2 or 3 bolts hold the stator plate on.

Probably just a variance in manufacturing

I'm

Depends. Typical is 10% +/- of the target value.

That sucks, because unless you know what the correct ohm ready should be, you won't know if a coil is out of spec. As stated in the video, it is the wired that is wrapped around the core that determines weather the magnets will induce a charge to them.

thejunkman I’m gonna look for a new one from another bike maybe, it’s just a pain because i didn’t wants to. But lifes not fair

I did 😉

+Shaine MacDonald "Generally" is the operative word. The color of wire is bike/application specific. Most vintage Japanese bikes are BLACK or BLACK/WHITE (striped). Always refer to the service manual for proper info, thus why I stressed this at the beginning.

I always use a service manual!

+Shaine MacDonald then your good to go!

facebook.com/thejunkmansadventures I also have a website with more information. www.thejunkmanadv.com/

If you read your service manual it will explain how to test just as I did. The other stuff is addressed in the video.