I hate my CDI

Discussion in 'Electrical' started by adrian101, May 13, 2011.

  1. adrian101

    adrian101 Member

    I have brought two speedo's and I'm 100% sure that my CDI unit is interfering with the speedo's. Both speedo's just blank out and die. I change batteries but they are dead.. Is their a CDI that will not interfere with the speedo or is it best for me to change to a speedo like the one below:

  2. hi i had the same perblom but it was my springer forks screwing then up
  3. gothicguy64

    gothicguy64 Member

    hi again

    im presently using a repco 9 corded speedo from bigw ....15 bux
    so far only a wireless speedo wont work becoz of cdi

  4. Al.Fisherman

    Al.Fisherman Active Member

    That appears to be a mechanical, and not a electronic speedometer. The ring that fits over the axle is what operates the needle, via cable. They don't or should I say I haven't had one that would last on these motorized bikes. Just because the needle can or shows it can register a speed (50mph) much faster then you can go, doesn't mean the speedometer gears can take it. Everyone that I've worked with had no battery. What battery are you talking about?
    Last edited: May 13, 2011
  5. adrian101

    adrian101 Member

    I had the same speedo LOL
  6. adrian101

    adrian101 Member

    The one's i've had previous where battery operated, repco 9f like the picture below:
    repco 9.jpg

    The other one that i showed early is a mechanical speedo that i was thinking of getting. but now that i know they may not be able to register high speeds then i won't worry about it. lol

    Once my motor is completely modded(sp) up i want to take it for a speed test without the speedo sh#ting itself?

    Do you know of any good ones?

    Attached Files:

  7. GearNut

    GearNut Active Member

    Some folks have had good results by relocating the CDI box to the seat tube. You may need a longer spark plug wire to do this.
  8. davidstipek

    davidstipek Member

    I had the same speedo... made in Tiawan. Speedo good for bike.... BUT!!! sending unit is excellant. I changed heads to a chrome MC unit, using cable that came with original package and retained axle/wheel drive sender (Lub it up good with a soap base lithium grease... sqeeze it in) I have chopper bicycle with 80cc Yamaha / semi automatic trans...no clutch. I have done extensive rides all over northern Thailand no issues speeds in excess of 80 kph. Keep excessive grease on it for the first 400-500 km and you will be fine. Just add it to Maintainence schedule (example: checking chain tentios and lubeing) My speedo head is from Honda Boss, cable fits perfectly!!

    Attached Files:

    Last edited: May 15, 2011
  9. adrian101

    adrian101 Member

    Is there anything i can put on my CDI to help stop interference? I don't know if its from vibrations or the CDI but its killing my speedo. I'm on my 5th speedo thus far :(
  10. davidstipek

    davidstipek Member

    Couple of questions first::detective:

    How close to speedometer and sender/pickup is CDI? (I am assuming it is magnetic impulsed)

    Try using cell phone close to CDI when Bike is running... Static?

    First make sure CDI has a good ground. You can also jumper ground from frame to Front fork. (This has been known to cure alot of Gremlins) Do your lights flicker? If so check all ground wire connections.

    If the first question answer is Magnetic. Go to computer shop and ask then for a small lead sheild pack just big enough to totally cover CDI. Then neatly fold and tape up like you are making Mothers Day Gift (So it looks neat... Not like a Red Neck did it :) ... OK?):bowdown:

    Let me know what happens. Also if speedo has any alectrical connection to Bike electrical system... Make sure it has good external ground. You can run to and connect to the jumper I hope you installed.

  11. retromike3

    retromike3 Member

    cdi and stuff

    what I did after my CDI killed my first speedometer was to get a shielded plug wire. It seemed to work pretty good. And yet I could still operate my tiny tach. Since then both electronic devices have failed( I think they both get too wet) but they were working for a while.
  12. rohmell

    rohmell New Member

  13. Lazieboy

    Lazieboy Member


    Hi, I got a walmart Bell platinum series cyclomputer for $21.36 after tax. order site to store and pay no shipping.