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Old 07-26-2011, 10:54 PM
Goofpod Goofpod is offline
Motorized Bicycle Newbie
Join Date: Jul 2011
Location: Northern CA
Posts: 2
Default New from Northern CA - Noise Question

Just finished the 47cc install of the generic Chinese kit. Oval, not too bad with some minor tweaks. Took some playing with the carb settings to get it right. Now, it's nothing but fun and waiting out the engine burn-in so I can open the throttle some more.

Question: Has anybody added an additional muffler pipe or had success with any other noise canceling approach? It's nowhere near the neighbor's annoying Harley but this is a bicycle first after all, and I very much favor being stealthy. Plus, I've noticed the drive train itself makes a fair amount of noise when pedaling- way more than I expected, in fact. Maybe that will settle down some over time? Seems like the crankcase resonates and intensifies the chain/sprocket noise and, since the chain is always active, there's no getting around that. (Forgive me if this has already been covered in archives)

Any input would be appreciated. Otherwise, it's a gas being powered now (no pun) and looking forward to learning from all you vets on this forum.

Warm regards and cool motored breezes,

- Goof
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Old 07-27-2011, 01:26 AM
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The_Aleman The_Aleman is offline
Motorized Bicycle Elite Member
Join Date: Jul 2008
Location: el People's Republik de Kalifornistan
Posts: 2,658
Default Re: New from Northern CA - Noise Question

Welcome to the forum!

You can get 1-2 of those $2.99 Fry's Electronics mousepads and cut it to fit behind the covers. Some people have used duct-tape covered cardboard.
You can also get them premade at if you check the forum sponsors on left or right. All the chinagirls have some engine noise and may even dance at high RPM! lol
Also grease the pin+ball behind the clutch arm cover, as well as between the gears behind the cover on RS of engine. I've always used automotive wheel grease.
If you're gonna pull the covers,to grease, might as well do up some sound deadening. Be careful with the gaskets ofc!

If you have any serious problems, feel free to make a thread in the 2-stroke section. There are many people who can help.
Chances are, someone has had same problem before, so you can find much with the Search function, too.
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Old 07-27-2011, 02:13 AM
Goofpod Goofpod is offline
Motorized Bicycle Newbie
Join Date: Jul 2011
Location: Northern CA
Posts: 2
Default Re: New from Northern CA - Noise Question

Thanks for the welcome and the tips. The mousepad seems like a good idea, I'll try that. I already greased everything up with wheel grease when I assembled it.

But, any thoughts on a longer baffle pipe, or some other stronger muffler approach? I noticed one important aspect I've always loved about bicycling is affected- you can no longer hear the cars coming. Obviously, you'll never get super low noise with a gas engine but I am curious to hear if anyone has tried anything. Without actually welding up a custom pipe- maybe one that curves along the bottom of the bike, two or three times the length of the stock pipe- it would be hard to modify what comes with the kit.

Also, anybody tried better air cleaners so you can ride on dirt? Lots of trails around here that I love to ride just to get across town etc.


- Goof
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Old 07-29-2011, 11:05 AM
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Ernst Ernst is offline
Motorized Bicycle Elite Member
Join Date: May 2011
Location: Turlock Ca
Posts: 363
Default Re: New from Northern CA - Noise Question

I know what you mean.. It's different noise on different motors I find.

The first motor I ran used stock mounts and this new RAW has a super beefed front mount. Lessons learned.

There are threads on cutting down noise. One guy extended the intake with a hose back behind the seat because there is sound from the carb.

I went with the Sick Bike Parts expansion chamber and direct the exhaust down under now.
The stock muffler seemed to aim the noise down and it came back up off the road..

Read up is what I recommend. You may find a solution.

Also what about the Poo Poo pipe guys? Puts the exhaust way back..
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baffle, loud, muffler, noise, quiet

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