Engine Trouble engine runs bad please help

Discussion in '2-Stroke Engines' started by tacotyler, Jul 17, 2013.

  1. tacotyler

    tacotyler New Member

    okay guys i have a 80cc china that ran great for a year no problems 1543 miles on it no problem i have a upgraded carb (rt) and a cdi of a old suzuki quad witch worked great higher, faster rev, ran cooler and more power. now one day i took it out and it started bad and while leaving my neighborhood, there was no power i would ride at a constant speed pull in my clutch lever THEN THE ENGINE WOULD REV REALLY HIGH THEN DIE for no reason? i checked for intake leaks none, cleaned my carb, checked plug witch was lean, checked for any head/cilinder leaking, i have the same compression. i put the old cdi on witch the engine still ran bad same problem. i just don't no what could make my engine with no load rev really high then die, i thought it might be a intake leak. okay well i think there could be a small seizure on the exhaust side causing drag witch could be making it run bad? i dont what it could be so any help would be awesome thanks :sweatdrop::shout::(

  2. Purple Haze

    Purple Haze Active Member

    You definitely have an air leak somewhere. Maybe one of the crank seals. With that many miles on the engine, I'd go ahead and change the bearings while you're there.
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  3. crassius

    crassius Well-Known Member

    yeah, sounds like a loss of compression - seals, or head gasket, or case gasket, or rings
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  4. jaguar

    jaguar Well-Known Member

    with mini-seizures often the rings stick in their grooves. take it apart and clean it and clean out the ring grooves.
    I would bet on you having a crank seal leak though
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  5. HeadSmess

    HeadSmess Well-Known Member

    ditto on those crank seals. check magneto/clutch housing for oil/fuel.

    if concerned about cylinder state, pop off head and check bore at BDC. any damage will be apparent and warrant further inspection... there will always be a minor scratch or two. ignore them ;)
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