Engine mysteriously stopped!

Discussion in '2-Stroke Engines' started by mattysids, Oct 15, 2009.

  1. mattysids

    mattysids Member

    My engine, after purring like a kitten for many miles

    has suddenly died with no warning or even sputtering

    I am pretty sure it is a cdi box failure but I'd like your input

    Here are the symptoms:

    -Only my most expensive plug passes spark test

    -It fires VERY rarely whilst pedaling my butt off, and only one revolution at that

    -Died very suddenly in the middle of a ride after a hard start earlier

    -Gas is clearly entering the chamber (checked float bowl and jet too)

    -All gaskets check out

    I pedaled so hard my pedal actually fell off!!!!

    help please!

  2. Check ground wire and spark plug wire on cdi box and all connections even the kill switch. Not sure but i think if cdi is bad its bad and wont work at all. Let us know what ya find please
  3. EnFlaMEd

    EnFlaMEd Member

    Mine died on me yesterday on the way to work. I checked everything I could and even redid all the wiring out in the field and tried two different plug leads and plugs. After about an hour of stuffing around with it I gave up.

    As I needed my bike to be fixed immediately so I could get to work today I went out and bought a new kill switch, magneto coil and CDI from RSE (life savers!). Replaced those items last night and its running again. I couldn't be stuffed trouble shooting parts. For the price I would just replace the lot.

    Just as a point of interest, my bike was wired using all the standard connectors in the fashion shown in the instruction manual. When I rewired it last night, I used my quality Utilux connectors and wired it the way that leaves the white wire unused.
  4. mattysids

    mattysids Member

    The timing seems wayyyy off

    I cranked it for a good 20 seconds before giving up, then out of the blue after about a minute the spark all of a sudden fired with a loud bang

    More evidence of CDI failure?
  5. wolverene13

    wolverene13 New Member

    I had the same problem...my engine just quit while I was riding down the street and wouldn't start again. I cleaned the spark plug, replaced the CDI, unhooked the kill switch, and replaced the spark plug with no luck. It turned out that the little plastic piece that goes around the wiring at the bottom of the engine came loose and water had gotten into where the magneto is. Didn't think the magneto could go bad being that it is just a magnet and some copper cable, but it did. Replaced the magneto and I was back in business.

    Good luck,


    DJEEPER Member

    That happened to me when the plug gave up the ghost.

    its definitely electrical....try a plug first. I was suprised!

    starts on 2nd pull
  7. tskrem

    tskrem Member

    how do you repace a magneto, im stuck. this has all happened to me.
  8. Al.Fisherman

    Al.Fisherman Active Member

  9. Al.Fisherman

    Al.Fisherman Active Member

    The only way timing can be off is for the magnet key to fail.