Home Forums 2-Cycle Racing Kt100 shutting off

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    • #87278
      Tom Petalino
      Participant

      cannot figure out what is causing my kt100 to run for about 3-5 seconds then shut off. Changed fuel, carb, filter, tci, plug. Still unchanged. Has spark out of cylinder, then put plug in and it runs for a few seconds then shuts off . Pull plug, no spark. Try agian same results. When it does  run, revs fine sounds good then  shuts off agian. Any thought where to start looking next?

    • #87281
      tony zambos
      Participant

      When you try to re-fire it and it doesn’t start, is the plug wet? Make sure there are no cracks in the pulse line. You’ll need more than two hands for the next check. While cranking the engine over, choke the carb. If it doesn’t start, there should be some gas dripping out the carb. When the engine doesn’t fire, can you get a spark grounding the plug to a fin? Pull the side cover off and check for a broken coil wire and for excessive up and down movement of the crank. If you have someone that can loan you a working coil, try it.
      When you turn the motor by hand, does it seem to have its normal compression? If not, pull the head.
      And don’t ignore the work you’ve already done. The new plug could be bad and the carb may not be assembled correctly.

      Good Luck

      LAD Specialties customer / tony kart / rotax / kt100

    • #87282
      Tom Petalino
      Participant

      When the engine shuts off the plug is wet. I pulled side cover off and noticed tci wire was cracked. Spliced back together and thought this was my problem. Plug sparked great agianst fin. Put all back together started right up fine then shut off agian after 5sec. Ill try pulse line tomorrow. I know the crank shaft has a slight bend to it. Ive been running it this way for long time. About 6hrs. I just practice with this engine. I accually run faster lap times with it but im afraid it will detonate soon.  Thanks for the reply

    • #87283
      Tom Petalino
      Participant

      Compression  was around 130psi with snap on gauge

    • #87343
      Tom Petalino
      Participant

      Update. Changed coil and im back in business.  Wierd how it would run for only a few seconds then shut off.  Runs good now.

    • #87345
      tony zambos
      Participant

      Thanks for the update. We had gone for years without ever having a problem with a coil until this year. At the exit of a high speed turn, the engine had a hesitation. Turned out to be the coil.
      Glad you sorted out your problem.

      LAD Specialties customer / tony kart / rotax / kt100

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