expansion chamber questions

crlefley

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hey guys, i know that expansion chambers are designed for certian cc bikes like a 47, or whatever, i was wondering would it hurt my bike (80cc actully 69 ) chineese motor to put one of those on, or should i look for a specific chamber for my engine?

also, anyone know where i could find a chamber to buy?

thanks
greatly appreciated
 

bluegoatwoods

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I'm no authority, but here's my understanding of it:

For an expansion chamber to work properly, it must be "tuned" to the engine. It needs to be a particular size (and likely, shape) to work with that particular engine. If you "mix and match", you're not at all likely to have something that works as well as it should.

The rest is purely my speculation: I'm thinking that if you put a chamber on that's not right, and if the "mix" is really, really off, then you're likely to be able to tell easily. Unburnt fuel coming out the exhaust, maybe terrible performance. But maybe a "mix" that's only a little bit off will work well enough, if not perfect. I'd say it's worth a try if you have one on hand.
 

Mountainman

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For an expansion chamber to work properly, it must be "tuned" to the engine. It needs to be a particular size (and likely, shape) to work with that particular engine. If you "mix and match", you're not at all likely to have something that works as well as it should.

But maybe a "mix" that's only a little bit off will work well enough, if not perfect. I'd say it's worth a try if you have one on hand.

bluegoatwoods has given you a fine answer to your question

just wanted to ask
are you truly up for the increase in noise level ???
these things can really wiss off the neighbors and POOOLICE

it's all in what you are looking for as we

ride that thing MM
 

isoxazole

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I picked up a used Polini exhaust w/expansion chamber for $50
It's on a polini clone motor and it screams louder now then with a HT exhaust.
 

crlefley

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just wanted to ask
are you truly up for the increase in noise level ???
these things can really wiss off the neighbors and POOOLICE

i dont really care about the noise level, if its really that much of a pain then ill just put on the old ht motor
 

Fulltimer

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Expansion Chamber Question

How much louder would a bike be with an expansion chamber as opposed to a stock muffler? Does anyone have a before/after video?

Terry
 

Fulltimer

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My post above was a stand alone thread. I received a warning because it was a duplicate. Then it was moved here. But, my question stands. Does anyone have a before/after video showing stock vs expansion chamber?

Terry
 

oologah

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I have the banana shaped one from Spooky Tooth. Yes it made my exhaust really loud, rigged a muffler on the end of it and that fixed it.
 

motorpsycho

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bluegoatwoods has given you a fine answer to your question

just wanted to ask
are you truly up for the increase in noise level ???
these things can really wiss off the neighbors and POOOLICE

it's all in what you are looking for as we

ride that thing MM

not of you put a baffle on the end of it, or modify the stock muffler to go over the end. My expansion chamber, with modified stock muffler gives a ton more power over the stock unmodified muffler, and my bike is no louder than your average weed eater.
 
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