80cc motor is back firing , jerking and dying.

Discussion in 'Motorized Bicycle Trouble Shooting' started by 68thumper68, Nov 8, 2016.

  1. 68thumper68

    68thumper68 New Member

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    these engine has been running fine for a week now. And today it lost power, started back firing, spitting, and died on me. Any ideas on the course of action I should take?:-||
     
  2. Agreen

    Agreen Member

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    Likely to be the ignition system. See if you're getting spark. If not, use a multimeter to check the resistance of the magneto. Check the condition of the spark plug, and also look for burning between the spark plug and wire. It's most likely the cdi, but at least test the other components before replacing any parts. You want to be sure.
     
  3. crassius

    crassius Well-Known Member

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    I'd first check head gasket & motor mounts.
     
  4. Slogger

    Slogger Member

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    Backfiring might indicate a timing problem, I would check the magnet's woodruff key, too.
     
  5. ezrider

    ezrider Member

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    How about a slack chain ??
     
  6. netsharpshooter

    netsharpshooter New Member

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    Hey, I build the Rocket Racing CDIs, I will sell you one today or tomorrow for $40 shipped. Just message me.

    There is a chance your oil mix is spitting on your air filter and fouling it up. you can try removing the air filter for a bit to see if you get the juice back.
     

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