Quiet as possible.

Discussion in 'Motorized Bicycle General Discussion' started by TomE, Aug 1, 2008.

  1. TomE

    TomE New Member

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    Trying to quiet down my engine as much as possible. The kit is a "80"cc Gofastboy kit. So far i've done the cardboard in the cover mod, the rubber in the fins mod, and tried to pack the muffler. Now most of my noise is engine noise. When i disassembled the muffler, the "guts" wouldn't budge. All i could remove was the cap and a 8" rod that is welded to it. The stud in the middle is attached to some stuff inside, but won't come out. I packed the muffler loosely with muffler packing glass. The exhaust didn't quiet down at all. Any help with reducing noise would be great.
     
  2. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    As a guy who just turned 50, I agree, stealth is best.

    I've tried that stuff. But nothing really worked.......in fact I got an expansion pipe and that sucker is even louder! Then I fabbed a muffler mount and hooked a small muffler up after the pipe silencer. Nice, really nice and quiet.
     
  3. jf30cp

    jf30cp New Member

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    sp polblo, let me get this strait, on the stock pipe, right on the end, you actually attached am small lawn mower or weed wacker after marker muffler? so you have two mufflers? and it works
    like this= header--------stock muffler-------after market small muffler ?????
     
  4. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    Oh no, it's: Matched header (pocket bike pipe ground and mini-drum sanded to open up and match the port) ------custom pipe expansion chamber------expansion chamber silencer with steel wool-------adapter------4 stroke threaded muffler.

    I get plenty of power AND quiet.

    I'll post some pics tomorrow. I have a ball game.
     
  5. Jemma Hawtrey

    Jemma Hawtrey New Member

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    You can get an adapter for the tanaka pipes that'll let you stick the stock muffler on the end of the pipe silencer to quiet it down... although it looks kinda strange..

    And I cant remember where I saw it..

    Jemma xx
     
  6. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    So you asked for some prototype pictures. Still in development as you can tell. Need to dedicate time to the bracket and such. Never mind the pro tape.
     

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  7. misteright1_99

    misteright1_99 New Member

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    I would be careful with the steel wool. It might get sucked back into the combustion area by the return pulse and scour the cylinder or worse. Fiberglass would be MUCH better. I used ordinary fiberglass wall insulation packed very loosely in the silencer I made....
     
  8. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    You think a sound pulse will go into the silencer and pull all the way back???
     
  9. misteright1_99

    misteright1_99 New Member

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    No but a pressure pulse could in theory create a negative pressure in the silencer. All the packing I have seen over the years has been a glass product, such as fiberglass. Just a thought....
     
  10. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    pressure pulse/sound pulse I used them interchangeably. Never the less, glass is harder than steel wool.....
     
  11. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Steel wool will BURN.

    Don't use it.

    To the OP- Experiment with adding an after muffler with some hose clamps and silicon or rubber tube and a mower muffler. You don't want to cut down on the flow too much, but you do want to increase the area of the muffler..

    Also, quieting the intake will quiet the bike. What sound do you hear when you twist the throttle? On every bike I have built with the china in-frame it has been the intake "roar".
     
  12. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    Maybe. Tightly packed in a silencer around a holed tube (not so many holes at that), doubt it.

    Chances of being sucked all the way in? Never.
     
  13. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    In the scenario you present, no, I don't think it will catch fire and burn. Shoved loosely into the cannister that has had the baffle removed it WILL BURN. I saw it happen....twice with two different engines.

    It should be better used to clean pots and pans.
     
  14. misteright1_99

    misteright1_99 New Member

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  15. Norman

    Norman LORD VADER Moderator
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    I have a muffler I made for my bike and for cruizer's bike and the are quiet ask cruizer. They are kind of labor intence to make and no packing of glass or steel wool.
    All you realy hear is the intake noise.
    Norman
     
  16. Andyinchville1

    Andyinchville1 Manufacturer/Dealer

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    HI,

    I had toyed with the idea of quieting things down before BUT I finally got some time to actually do it......After testing this set up I remember cursing the loud ebikes as I whizzed by them! ;-0

    Andrew

    PS - I am going to put a rain cap like tractors and big rigs have on the muffler
    Other things that need to be done : intake silencer, rubber on clutch cover
    and rubber blocks in the fins....The exhaust noise is now taken care of ;-)
     

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    #16 Andyinchville1, Aug 18, 2008
    Last edited: Aug 18, 2008
  17. misteright1_99

    misteright1_99 New Member

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    rotfl That works too..........rotfl:rolleyes::eek:
     
  18. vegaspaddy

    vegaspaddy New Member

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    WOW, thats one mighty big exhaust, cover it with prism mirrors and you will have stealth mode.....
     
  19. Pablo

    Pablo Master Bike Builder & Forum Sponsor

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    Andy - that's hilarious. Does it sound like a tuba with bad gas? rotfl
     
  20. Norman

    Norman LORD VADER Moderator
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    Now all you need is a big chrome stack and air horns oh ya don't forget the cb radio.rotfl
     

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