Engine Trouble wont idle

Discussion in '2-Stroke Engines' started by rj1967, Jun 7, 2015.

  1. rj1967

    rj1967 Member

    I have an 80cc that wont idle after it warms up. Dies every time I come to a stop. I think the problem is where the throttle screws on top of carb but not sure. Idle is all the way up and still stalls at stop. Also have a little slack in throttle. Can anyone tell me in me in laymen terms how to fix this? Thanks.
     

  2. Slogger

    Slogger Member

    Problems that crop up when the engine is hot generally mean it's too rich. My own bike didn't like to idle down and hold it until it was leaned out after break in time was finished. I'd pull up to a stop sign and *BUP* it quits. Then it would start right back up.
    How's your engine running? Does it always run in 2 stroke or is it 4 stroking a lot?
    You might also want to check your spark lead is making good contact at the plug and at the CDI.
    Take the air cleaner off and operate the throttle, looking for the slide to rise and fall smoothly all the way.
    Dirt in the carb (especially in the main jet or the float needle and seat) can cause it to run poorly also.
    Hope you get it sorted out.
    Regards!
     
  3. crassius

    crassius Well-Known Member

    yes, too rich is probably it - drop your needle down one slot & you'll probably be able to back out your idle screw quite a bit & still have good idle speed
     
  4. rj1967

    rj1967 Member

    My needle is set on the notch closest to
    the point..im assuming to get a little leaner I need to come up one notch..is that correct? Thanks guys
     
  5. Slogger

    Slogger Member

    Yep, and maybe two notches..
    Raising the clip drops the needle, leaning it out.
     
  6. rj1967

    rj1967 Member

    Ok ill try it. Thanks
     
  7. rj1967

    rj1967 Member

    Ok..got good idle but loss of power. Anyway to compensate?
     
  8. crassius

    crassius Well-Known Member

    depends on whether motor has gotten around 300 miles on it yet - I rarely even try to tune them till then

    if it is run in, then try one less notch on needle - if better, good, if worse, the float level can be adjusted to get about the same as a half-notch

    all else fails, it's time to think about a new main jet
     
  9. rj1967

    rj1967 Member

    Definitely run in. Float I think..need to push clip in a little or pull out a little?
     
  10. crassius

    crassius Well-Known Member

    turn carb upside down - standard is with main jet just peeking up thru float - leaner is jet just hidden by float - richer is jet sticking well up thru float
     
  11. rj1967

    rj1967 Member

    I did find out one thing..if you flood the motor it takes an act of God to get them unflooded shy of taking off muffler and letting it drain out.
     
  12. rj1967

    rj1967 Member

    Can anyone tell me a quick way to unflood this 80cc stubborn *****? Please?
     
  13. crassius

    crassius Well-Known Member

    take out plug & pedal it a bunch - when you get it to a point at which it will start, just keep it running for a few minutes till it drys itself out inside
     
  14. rj1967

    rj1967 Member

    Ill give it a shot. If that dont work anyone got a shotgun? That'll fix it right up.
     
  15. KCvale

    KCvale Motorized Bicycle Vendor

    What gas : oil ratio are you running?
    I find 25:1 for a gallon break-in, and then 32:1 synthetic from then on.
     
  16. rj1967

    rj1967 Member

    About 6oz to every gallon. However that measures out. been broke in awhile.
     
  17. KCvale

    KCvale Motorized Bicycle Vendor

    Way too much oil, run 4oz, 1/2 cup.
     
  18. butre

    butre Well-Known Member

    I tell people to run 32:1 because any less is too scary for a lot of people but I run 50:1 with no problems. the 16:1 suggestion is just for people who don't want to rejet.
     
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