buckmcp

Discussion in 'Introduce Yourself' started by buckmcp, Nov 30, 2009.

  1. buckmcp

    buckmcp New Member

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    Hello, I am a newbie and have built one motorized bike and enjoyed it much. I am an old retired man getting up in age. I have a problem and hope some one can help me. I have purchased a 49cc made in China engine and have it installed and riden. However the engine runs too fast with throttle closed almost uncontrollable. I have very carefully examined the carb and can find only one adjusting screw.which make no difference while adjusting. Everything I read says there should be a high and low adjusting screw. How can I get the engine slowed down? Thanks for any help.
     
  2. 2door

    2door Moderator
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    Buck,
    Welcome to the forum. Hope you enjoy it as much as we do. I'll try to help you here but in the future please post technical questions in the 'Trouble Shooting' section where it will get faster response.
    The small screw you mentioned is only to set/adjust the engine idle speed. It screws in to raise the idle and out to lower it. If your engine is running too fast and the screw does not help the next place I would look is at the carburetor slide or barrel. Remove the air cleaner and look down the throat of the carb while twisting your throttle grip. You should see a dark colored cylinder lifting and lowering. Often the problem is a kinked or misadjusted throttle cable. If you had the carburetor apart its also possible that the slide/barrel was installed backwards. There are two slots in it. The longer slot goes to the right side of the carb as viewed from the top looking down. The shorter slot, the idle speed slot goes to the left. One other thing that will cause a high idle speed is an air leak in or around the carburetor and/or the intake manifold. Make sure you have a good seal where the carb attaches to the manifold and the manifold to the cylinder. Take a look at these things and get back to us with what you find.
    Tom
     
  3. buckmcp

    buckmcp New Member

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    Thanks , Tom, being new to two cycle engines and the forum, but very mechanical minded, I finally found the carb slide was not going all the way down. I straightened out the cable and fixed the problem. Now if I can figure out how to shorten the cable. I will enjoy the forum and riding. Thanks a lot. Buckmcp
     
  4. 2door

    2door Moderator
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  5. Dave31

    Dave31 Moderator
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    Hello buckmcp, and Welcome! Glad to have you with us here at Motorbicycling.com
    dnut
     

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