No Spark

Discussion in 'Electrical' started by mshunk93, Jul 2, 2013.

  1. mshunk93

    mshunk93 New Member

    Lately, I've been having issues with the ignition on my 66cc gt-5 engine. One day while test driving my bike after changing the chain, I depressed the clutch lever and the motor shut off. After this, it would not start again. When I got home, I pulled the spark plug and it was cracked in half due to the way it sets up against the frame (clearance issues.) Thinking this was the problem, I bought two new NGK B6HS plugs. Still no spark.

    After this, I came to the conclusion that the CDI was bad and bought a new Jaguar CDI. After installing this, still no spark. So, I ordered a new spark plug cable just to be safe and a new magneto after whipping out the multimeter and determining that it was faulty.

    This morning, I installed the new magneto and it started right up. I rode it around the block a few times (running better than ever too) and parked it (with the gas on admittedly) to have a smoke. When I tried to start it back up, no ignition. Best I could get was a few sparks. Pulled the plug with the wire attached and placed it on the engine and pushed to see if it would spark. It didn't. All the electrical connections are good and everything seems like it should work but alas, it does not. The only things I could think of at this point is the magneto clearance (the bottom of the wheel is darn near touching the outer piece while the top has at least 3x this gap), and the spark plug wire (hasn't arrived yet.)

    Any thoughts as to what might be causing this issue?

  2. HeadSmess

    HeadSmess Well-Known Member

    so, magneto....old style with the white wire? or new style with just the blue and black?

    old one, i guess you lucked out and it fried pretty early on? if it has that white wire, cut it off and do not use it! short the blue to the black, or simply "cut" the blue for the killswitch! old style instructions say use the white for kill. old style magnetos have a bad join for the earth and burn out when the kills used too much... :rolleyes:
    if its a new idea. check and make sure its got a decent reading like 300 ohms.

    the wire wont make a difference. full stop. when working properly, the magneto can jump a half inch gap or more! if the wire has a small break in it, it will make what used to be used on old points ignition...a spark enhancer! high voltages act funny like that.

    while its good to set the magneto central, its never been an issue in my experience? loosen bolts ever so slightly, gently lever or tap in place, re tighten screws. being a wrap around type, clearance isnt critical, unlike brushcutters that need a few thou clearance.
  3. Big Red

    Big Red Active Member

    Nothing to add yet, headsmess pretty much covered it so far. But just out of curiosity I'm gonna follow this thread. It WOULD be just plain bad luck to have a new coil go bad this fast, but it could happen. I don't know how the new manual says to hook up the kill switch, But one wire to blue, one wire to black. Never ground a wire to the frame. I've seen that in some of the older manuals.
    Big Red.
  4. mshunk93

    mshunk93 New Member

    Well, the other morning I was fiddling with my bike and I decided to redo all the connections (resoldered the magneto as well,) but really didn't change anything aside from using wirenuts between the mag and the CDI. I got it to run for a minute before it cut out on me. After about 5 more minutes of tinkering, I got it to start up and I took it for a little drive to a friend's house a few miles away. An hour later, it started right up at his place and has been working ever since. Replaced the spark wire with a cool looking new blue one too and gave the wiring a permanent installation. As for the killswitch, I actually had it disconnected during this whole process to eliminate that as a source of failure. But rummaging through my toolbox today, I found a rocker switch that has a spring on one side and is normally closed that will do nicely to cut off the blue wire in-line.
  5. jaguar

    jaguar Well-Known Member

    the connection of the stator coil to the engine completes the electrical circuit of "ground" for the spark plug.
    use sandpaper on all 4 screw locations for a good long-lasting electrical connection there.
  6. Big Red

    Big Red Active Member

    Good advice.Then hook it up like this.

    Attached Files:

  7. Roykinn

    Roykinn New Member

    Same exact problem, still no spark!! :(


    I am having the same mystery as you, no spark all of a sudden, replaced the spark plug twice and the cdi, I am using the old style magneto with the white wire. I tested the ohms on the magneto at ~320 and the wires look fine to me. Still no spark, what kind of tinkering did you do that you think fixed the problem?

  8. Big Red

    Big Red Active Member

    Most of the time it's the coil. It either failed or developed corrosion on the grounds. (what you tested is the COIL, not the MAGNETO.) The MAGneto is the MAGnet in the center of the COIL.
    So, Remove the coil, Sand or scrape everywhere metal touches metal, including the black wire connector. Disconnect the kill switch and solder everything else together for now. Make VERY sure no wires are touching anything. Put a new plug wire and boot on it and see what happens. If it is a bad connection this should do it. If not and yer still getting 320 out of the coil then it's probably the CDI unit. These don't go bad as often as coils, but they DO go bad. I always keep one of each (coil&CDI.) in stock just for my personal bike. I hate waiting a week to ride my bike.
    Big Red.
  9. jaguar

    jaguar Well-Known Member

    stock CDIs are very marginal at best. If the magnet has lost some strength then the magnetic flux that powers the stator coil may not be enough for it to output enough voltage to the CDI. Stock CDIs have overly advanced ignition timing which causes higher peak pressure/temperature in the cylinder. This causes excess engine temperature. People have reported over 500 degrees F as a result. This paper says that heating a ferrite magnet over 460 degrees causes it to lose magnetic strength. So you need to replace it and, for god's sake man, get a Jaguar CDI! :)
  10. Roykinn

    Roykinn New Member

    more troubleshooting...

    Thank you for the advise Big Red,

    The first thing I replaced was the CDI, when I did so I did not know about the order in which you are supposed to hook up the wires from coil to cdi and may have done it backwards, causing this new CDI to malfunction. Today I tested compression, it was fine. I also took to nut off the magnet to check and see if it had shifted over some, but the magnet key seems to be aligned properly.

    I have cut off the white bulb wire completely from the coil and am going to re-wire it and solder everything together. I will also find out how to measure the CDI to make sure its not the culprit, I can do this with a multimeter I suppose.

    If there is anything I'm not checking let me know. Thanks for the help,

  11. BigBlue

    BigBlue Active Member

    Push the kill switch while trying to pedal start the engine. Sometimes they stick. My 2004 48cc does this every once in a while, usually I kill the engine by releasing the clutch. If I use the kill switch, sometimes it doesn't start until I pedal and push the kill switch several times.

    If you want to test the CDI unit, here's a no-start guide to help you along. You can test it with a DMM.

    If you've rode your bike in the rain or it has gotten wet, it's a possibility that your magneto coil and magneto rotor have become corroded. This may be a cause of a no-start condition. The only way that I know of testing the magnetic strength of the magneto rotor is to test it before hand with some steel nuts as a baseline, like this:)

    Good Luck,

    AKA: BigBlue
  12. Big Red

    Big Red Active Member

    Hey Jaguar, Read post#1, He already bought a Jag CDI.
    And good one BB, I don't know how accurate this would be or how many nuts together means it's OK, But if ya start with a brand new one, See how many nuts it holds, then you MIGHT get a general idea of Magneto health.
    And unless the engine was overheated for an extended period the magneto is probably OK. Your gonna have to ask Jaguar if hooking up his CDI backwards would hurt it any. If it does, (just a suggestion,) get a new stock CDI to test the theory, If it runs THEN invest in a new jag CDI. And DON'T hook the wires up backwards again.LOL. (blue to blue, black to black.)
    But, Like I said, MOST of the time IT'S THE COIL. If you were using the white wire at all the coil could have been weakend or completely destroyed. I've put a plug against the head, Got what LOOKED like a good spark, and still NO START, (weak coil.) You might want to keep an extra one around anyway and they are only about $12. Also, If you look closely at the coil you'll see where the tiny copper wire is soldered to the frame of the coil. This is what's commonly known as a "cold solder" connection and is notorious for loosing it's connectivity. What can I say, Just another example of Chinese quality control.
    Big Red.
  13. Roykinn

    Roykinn New Member

    resoldering the coil to frame connection

    Thank you all for you input, truly appreciated,

    Big Red, I never had the white wire in play and have now completely removed it. The copper cable soldered to the coils from is not broken but the metal is darkened and looks really thin, could this be re-soldered?

    Big Blue (any relation?), I have been doing all these tests with the kill switch disconnected so I don't see how that could be the problem :/

    Thanks again everyone-
  14. Big Red

    Big Red Active Member

    Then if the kill switch is still in play, Disconnect it. I've had a bad switch fool me more than once. And I've tried to re-solder that connection with little positive results. To do a good solder you have to heat the coil TO MUCH to be good for it. I think thats why they do a cold solder. If you have ANY doubts about the coil, Then it's probably THE COIL. So roll the dice for $12 and order a new coil. That is AFTER checking (by disconnecting,) the kill switch.
    $11.87 with free shipping from BGF. FAST SHIPPER

    $11.70 from PCC with free shipping, Can't remember how fast he ships.
    Big Red.
    P.S. BB's a good guy,But no relation.
    P.S.S. It's too early, Need more coffee. I read you had the kill switch disconnected then "brain Freeze" I guess.
    P.S.S.S.S....S. IT'S THE COIL!!!!
    Last edited: Jul 16, 2013
  15. HeadSmess

    HeadSmess Well-Known Member

    too true. the former melts unless you have a glowing red plumbers iron... and then it melts just because! i managed to be able to graft a length of wire on these old soldered ones and attached the standard black wire here.

    spend the dollars ;) so much easier.

    on these new ones with just the blue and black, you dont need the engine connection. im up to just soldering the cdi straight to the coil and forgetting about having an "earth". killswitch? i dump the clutch :) killswitches always break. only handy for doing throttle chops in my situation at which i install a real toggle switch.

    only thing thats stopped me rewinding one of these things is pulling the laminated core apart! they just dont want a bar of it! old tube transformers are simple in comparison! but i would like that power winding back with a bit more current capability... ie, not inclined to burn out and ruin a coil! the biggest problem is that both coils have a common earth. should be isolated. quite easy to wind the coil...just not while on the core :( to try and make a ferrite core would be interesting but a bit outside my capabilities as of this moment. maybe when i get my profile cutter running? :)
  16. Big Red

    Big Red Active Member

    Like HeadSmess said, "spend the dollars, so much easier."
    All I have to say to that is..... YUP.
    Big Red.
  17. Roykinn

    Roykinn New Member

    ordered parts

    Thanks everybody,

    I went ahead and ordered a new coil from Pcc Motors, hopefully I can get this up and running soon.

    I had mentioned early about wiring the cdi to the coil backwards, what I had meant was I may have put black to black before blue to blue, in the grubbee literature it says "First install Blue & Black wires from engine magneto to same color CDI wires. Warning: Do not hook up backwards or damage will occur to the CDI."

    I took this to mean hook up blue to blue before black to black, what I'm thinking now is it means simply dont connect it blue to black, black to blue. If I misunderstood then my cdi should be just fine.
  18. Big Red

    Big Red Active Member

    Big Red.
  19. Big Red

    Big Red Active Member

    I didn't mean to put a stop to the thread bro, And I wasn't laughing at you. I was just thinking (at the time,) that an electricion could wire an entire house wrong and backwards and it would be fine, Untill the power was turned on.
    So as long as the power wasn't turned on, your bike is fine.
    Big Red.
  20. HeadSmess

    HeadSmess Well-Known Member

    doesnt matter what order you join them up in :jester: as long as you join em to the right colour!

    and with the electrician quip...i always forget which terminal is active... considering most things run a transformer on mains, it doesnt matter. anything else runs a bridge rectifier...i have not found ONE appliance (a safety switch isnt really an appliance?) that requires the neutral and active be wired correctly! just dont hook active or neutral to earth or each other! i love AC :)