Carb/throttle needle valve adjustment

Discussion in 'Motorized Bicycle General Discussion' started by meowy84, Oct 18, 2010.

  1. meowy84

    meowy84 New Member

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    Oh great Happy-Time gurus lend me your wisdom. :) What's a good starting point for throttle needle valve for the first start and the break-in period? I'm finally about to get my Zoom 80/66cc going for the first time and want to minimize the initial hassles. My needle valve has the 5 grooves and the circlip is on the middle one straight from the factory. Obviously since that little valve has a lot to do with the leanness/richness of the mixture I'd rather have it a bit on the rich side for the break-in so I'd rather lift the valve a spot rather than dropping it a spot. Else, leave it in the middle as it is.
     
  2. charles kohler

    charles kohler New Member

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    start from from where it now is , at 24 to 1 mix with syn oil . run ror a few miles & then pull out the spark plug and check the color ,black is rich or or too much oil. try this first
    then adjust from there
     
  3. 2door

    2door Moderator
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    Second notch from the top is a good ball park starting point. As suggested above, after a few miles, a couple of tanks of fuel, check your plug. Very dark indicates a rich mix at which point you might consider raising the 'C' clip a notch but only after a few miles. Two or three tanks of fuel will tell the story better than just a tank full. Don't be afraid to twist that throttle either. Run it hard a few times; it won't hurt your engine and will reduce the break-in time. Running too soft for too long will not help a thing and can keep the rings from setting properly. They're tough little motors and like a little abuse.
    Tom
     
  4. meowy84

    meowy84 New Member

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    As always thanks for the info everyone.
     
  5. surfishjoe

    surfishjoe New Member

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    I will bump this since I am in the same boat. Dialing in the fuel mix is tricky for a newbie, my plug was definitly on the black and mucky side.
     

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