engine gets LOUD at full throttle

Discussion in 'Motorized Bicycle General Discussion' started by Crysisfreak7, Jun 21, 2014.

  1. Crysisfreak7

    Crysisfreak7 New Member

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    i recently moved the engine to a new bike, and when i hit full throttle, the bike vibration increases dramatically, and it sounds like sometihng is rattling around. this didnt happen on the other bike. it doesnt seem to do this while reving but i cannot be sure. and it only happens when i reach full speed.
     
  2. Crysisfreak7

    Crysisfreak7 New Member

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    my previous bike was a superlight, the new one is a beach cruiser
     
  3. crassius

    crassius Well-Known Member

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    sometimes one needs to redo cruiser mounts to get a good fit that will handle the vibration
     
  4. Crysisfreak7

    Crysisfreak7 New Member

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    what would best, leaning more towards the front bar, or more towards the back bar? (more towards the handle bars or the back wheel)
     
  5. Greg58

    Greg58 Well-Known Member

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    The best way to mount the engine is with the rear mount seated to the angle of the seat tube then make adjustments to the front mount. The more contact you have at the rear mount the less likely you are to have problems. I like to install the rear mount till the engine barely slides up and down , then get where I want it above the pedal chain guard then measure and make a spacer for the front mount. Since most of the low end frames all have different seat tube angles all the front mount spacers I have made were slightly different.
     
    #5 Greg58, Jun 21, 2014
    Last edited: Jun 21, 2014
  6. crassius

    crassius Well-Known Member

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    you really only have the option to move the engine higher or lower while keeping the rear mount perpendicular to the frame

    moving it a 1/4 inch up or down may get you a spot where the frame cancels out some of the vibration - it's a trial & error process to see if there's a better spot - most of the time, the lowest possible spot is best, but not always
     
  7. Theon

    Theon New Member

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    Just a thought, Are your wheels true?
    Maybe not an engine issue?
     
  8. The_Aleman

    The_Aleman New Member

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    As mentioned above, it's definitely important that the engine sits flat on it's motor mounts against the frame. Not only does this reduce vibration, it can keep the frame from breaking down the line. Many cruiser frames don't allow this on both front and rear mount, so you might want to invest in something like SickBikePart's universal motor mount:

    http://www.sickbikeparts.com/catalog/product_info.php?products_id=85
     

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