Quiet as possible.

TomE

New Member
Jul 7, 2008
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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.
 

Pablo

Master Bike Builder & Forum Sponsor
Dec 28, 2007
3,664
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Duvall, WA PNW
www.sickbikeparts.com
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.
 

jf30cp

New Member
Jun 23, 2008
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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 ?????
 

Pablo

Master Bike Builder & Forum Sponsor
Dec 28, 2007
3,664
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Duvall, WA PNW
www.sickbikeparts.com
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.
 

Jemma Hawtrey

New Member
Dec 29, 2007
288
2
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Essex, UK
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.
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
 

misteright1_99

New Member
Mar 21, 2008
716
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Treasure Coast, Florida
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.
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....
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
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".
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
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.
 

misteright1_99

New Member
Mar 21, 2008
716
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Treasure Coast, Florida
You don't want to cut down on the flow too much, but you do want to increase the area of the muffler..QUOTE]

Exactly, by almost doubling the inside diameter of the silencer there is more room for extra packing and more capacity for the sound waves to expand before exiting therefore cutting the noise dramatically. Also the smaller stock silencer that came with the chamber had very dense fiberglass, packed very tightly, which also didnt help...
 

Norman

LORD VADER Moderator
Staff member
Jan 16, 2008
2,605
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pampa texas
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
 

Andyinchville1

Manufacturer/Dealer
Dec 26, 2007
502
1
18
Scottsville, VA
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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misteright1_99

New Member
Mar 21, 2008
716
0
0
Treasure Coast, Florida
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 ;

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