My CDI hates me

Discussion in 'Electrical' started by Tank352, Apr 23, 2016.

  1. Tank352

    Tank352 New Member

    So I ordered a brand new kit. Installed and did a 4 tank break in. Bike was running perfectly. Went on a 20mile ride. After a 45 min break decided to return home. Now it seems my CDI is making a sound I can only describe as scatching/sqeaking/arching. When I WOT no noise whatsoever. Starting off noise. Low Rpms Noise. Idle no noise.
     

  2. Hello Moto!

    Hello Moto! Active Member

    That's weird. At least they're cheap..like most parts for these retches.
     
  3. Tank352

    Tank352 New Member

    Update... Put on a new CDI.. same noise.. Changed plug.. Same noise... Gonna play a game now called find the noise...
     
  4. Timbone

    Timbone Active Member

    I'm thinking that the little gear inside the clutch cover (main drive) may be loose, kicking out a bit and hitting the clutch cover. I wouldn't think that the CDI could make noises, at least not like that.
     
  5. Legwon

    Legwon New Member

    does it make the sound when you rev it (no movement)? if so take a screwdriver and use it as a stethoscope to find the noise, could be anywhere.
    If no, look towards the drive section(rear of the engine). could be inner clutch, clutch pads, drive axle, chain, drive gear....those are all items that move when clutch is released.
     
  6. Tank352

    Tank352 New Member

    Well whatever it is definitely is giving me a run for my money... Went for a ride yesterday with no issue. Stopped at a store for a drink. Disengaged my clutch started to pedal engaged clutch and nothing. Stopped and checked my clutch cable. Snug. Took off clutch cover. Clutch engage and disengage fine. However the engine now turns over when I push the bike even when the flower nut bottoms out. Motor turns but wont start.
     
  7. 45u

    45u Active Member

    Did you pull the cover and look inside to see if you see anything where the stator and rotor is? IF not that would be the first thing I would have done. I do not see where the CDI would make any noise.
     
    Legwon likes this.
  8. Tank352

    Tank352 New Member

    Yea nothing. I cant even get it started to check now... Im assuming rings or head gasket is screwed. Thankfully I have 2 spare motors for parts.
     
  9. 45u

    45u Active Member

    You can check for spark with out starting it. Jack it up right under the kickstand take the plug out put it in the plug cap set on the head engage clutch and spin it over with the rear wheel or with the pedal. This is how I do it but I do have a rack to make it easier to work on.
     
    Legwon likes this.
  10. 45u

    45u Active Member

    Did you re-torque the head nuts to the proper specifications? If you run an aluminum head gasket you will have to re-torque ever 20 or so miles this is why I went to a copper gasket.
     
  11. Tank352

    Tank352 New Member

    Im not even sure what the correct torque would be...
     
  12. 45u

    45u Active Member

    Torque 8mm to 120 to 175 INCH POUNDS
    Torque 6mm to 60-70 INCH POUNDS
     
  13. jaguar

    jaguar Well-Known Member

    stock heads are warped so it don't matter what gasket you use or what pressure they are torqued to.
    you have to use sandpaper on glass to plane the head flat.
    also see my ignition troubleshooting guide: http://www.dragonfly75.com/motorbike/testCDI.html
     
  14. 45u

    45u Active Member

    I understand this and checked my head and cylinder and it was fine well not that bad anyhow. If it was perfect you would not need a gasket. I have worked on many a 2 cycle motrorcycle engine that did not even use a head gasket. When I replaced nothing but to a copper head gasket funny how I now longer have to re torque other then once after about 20 miles like I did every time I rode with the aluminum?

    I MILL my heads on a milling machine and not the ancient Neanderthal age way with glass or sand paper. I only talk about glass and so on trying to help those that do not have access to a MILLING machine.
    Jeff
     
  15. butre

    butre Well-Known Member

    I do have access to a milling machine but I still usually go with the glass and grinding compound method. milling machine is quicker but you'll never get a mirror finish with one.

    if I'm decking the cylinder I'll mill it down, just trying to make it seal it's getting the glass and grinding compound.

    none of my engines have head gaskets, they just don't need them.
     
    Timbone likes this.
  16. 45u

    45u Active Member

    Really do not want a mirror finish. The little a mill leaves behind only help to retain the gasket. One of the things I wish I had is a mill but have a friend that has several.

    Here is a case we fixed. The lip for the o-ring was 90% missing. Weld and machined.

    [​IMG]
     
  17. butre

    butre Well-Known Member

    when you're running without a gasket you want it as smooth as possible. mirror finish is a hyperbole but gives you an idea of the level of detail attainable.

    here's a rechambered slant head I was working on before my camera quit on me. I still had some work to do on the squish band and one more stage of polishing to do, but you get the idea.

    [​IMG]

    you never realize how bad the stock heads are until you attempt to rework one, tons of little bubbles in the aluminum and the finish on all of the surfaces are horrible.
     
    Timbone likes this.
  18. sully1617

    sully1617 Guest

    in the auto motive field when we run into problems like yours sometimes we wait til after dark or turn out the lights in a darkened garage then start the engine and spray the wires (in your case Wire) with plain old water. if your have a bad plug wire or exposed power wire it will show itself as a spark. you should not see a spark at all anywhere. if you do replace whatever is doing it and that will solve that. however i have never ever heard of a cdi making noise and suspect that what you are hearing is caused by another component on your ride. you can take a piece of cardboard and place it in front of your bike piece by piece to block out noise locally and try to identify the noise location that way and it won't cost a thing. use it like a shield so to speak.
     
  19. Timbone

    Timbone Active Member

    I
    Thank you for this picture! I am going to invest a few hours if elbow grease to see if I can replicate this!
     
  20. Tank352

    Tank352 New Member

    Found my issue. Blown head gasket... Let it sit for a few days and took a closer look.
     
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