how to make an engine quieter/stealth

DannyBOY

New Member
Jul 18, 2010
7
0
0
Manchester
hello poeple of this forum!!!! :D

right, where i live in manchester in the united kingdom they have legal requirements for you to be able to ride a bike with an engine. so i was thinking if i make the engine as quite as possible they would never know that it has an engine built on to the bike and i would be happy and they would be happy beocuse they would never find out. i live in a place where there is hardly no police anyway beocuse i live in the county. but yes.

is there any way of making the engine more quite because i have seen some videos and their engine seem's pretyy load, ive read alot about losing power of the engine but im really aint that bothered about that beocuse as long it's quite and hardly no body can here it i anit bothered.

alot of the threads what ive read are all back in 2007-2008 so i was thinking has anybody got any new ideas about to make the engine very quiet????


i will be looking forward to your post's


Cheeeeeeer's

:-||
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
233
63
up north now
Not much is new on that front.

Rubber in the fines, cover the gearcase with a mouse pad, make an after muffler, and quiet the INTAKE NOISE.
 

Goat Herder

Gutter Rider
Apr 28, 2008
6,248
10
38
N.M.
Welcome to the forum! Just Running 3/8 inch conduit from the mufflers out put all the way to the back.[Easy stuff to bend] Will cut noise way down it will cut some power Though. Do something along those lines with two mufflers and a little bigger pipe. You'd be surprised. It will be as quite as a little honda generator.:)


Here is what our search engine brought up. Seams a bunch of reading to weed through though. [sorry]
Others will soon pipe in!

quite muffler - Google Search
 

Thud

New Member
May 26, 2010
205
0
0
West Michigan
Running an electric will be the "quietest" option.
The only negative is the range issues & upfront costs. A small hub motor & discrete batt pack are totaly stealth.

All my electric bikes (no hub unites-RC powered)will embaras my china bike motor unit off the line & at top speed.....untill we hit the 15 mile marker.........
 

BarelyAWake

New Member
Jul 21, 2009
7,206
9
0
Maine
Most folks don't seem to mind the noise of their own bike, in fact many make them louder in the quest for power lol ... but I ain't one of 'em ;)

The above suggestions are good 'uns, here's a lil more on the subject;

http://motorbicycling.com/f4/remote-airbox-intake-silencing-cheap-10967.html

...and quieter doesn't necessarily mean a loss of power;

http://motorbicycling.com/f3/whats-difference-20708.html#post197273

Bear in mind that no any one mod will silence the motor completely, much like performance modifications it teds to be a buncha lil things that add up. I'm a big fan of coating the inside of clutch covers with rubberized undercoating (automotive product, 3M brand is pretty good) for example - add Joe's mouse pad idea to quiet even more...
 

2door

Moderator
Staff member
Sep 15, 2008
16,326
123
63
Littleton, Colorado
Joe's mention of intake noise is important here. The pop-pop-pop sound that comes from the carburetor intake is often understated when talking about quieting the engine. As Barely Awake links, a remote air box, properly insulated and piped to the carb will go a long way in reducing the noise from your bike. I've experimented with several options and the one that works well for me is not only simple but also adds to the aesthetics of the air inlet. Rattle can, spray paint, can tops come in every color you can imagine. They can be installed easily with a long self tapping screw into the stock air cleaner housing. I wrap the inside with a thick felt that seems to absorb a lot of the pop-pops and it looks better than the black plastic air filter. Of course there are other options but give this a try. I'm not sure if spray paint comes in the same containers in Great Briton but any plastic can top that will fit over the air cleaner with space for padding will work.
Extending the exhaust pipe and installing the muffler at the end is always quieter than the kit pipe and muffler but requires some welding. Good luck. Let us know if you come up with anything new.
Tom
 

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taddthewadd

New Member
Mar 1, 2009
339
0
0
39
Visalia, California
I guess I could get my bike running and place some felt in my hand and press it up against my sbp low pro filter and see first how much noise is reduced and then if I want build it like yours.
 

2door

Moderator
Staff member
Sep 15, 2008
16,326
123
63
Littleton, Colorado
Tadd,
I've experimented with the cover on and off and I can't discern any difference. The stock air cleaner only draws in air through the four tubular openings at the bottom and the cover I put on doesn't effect them, only the thin plastic housing. My theory is the intake noise is amplified somewhat by the stock cover. Keep in mind that my idea doesn't make the engine silent, just a little quieter, especially from the intake noise.
Tom
 

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,508
6
38
Ridin' inSane Diego, CA.
Joe's mention of intake noise is important here. The pop-pop-pop sound that comes from the carburetor intake is often understated when talking about quieting the engine. As Barely Awake links, a remote air box, properly insulated and piped to the carb will go a long way in reducing the noise from your bike. I've experimented with several options and the one that works well for me is not only simple but also adds to the aesthetics of the air inlet. Rattle can, spray paint, can tops come in every color you can imagine. They can be installed easily with a long self tapping screw into the stock air cleaner housing. I wrap the inside with a thick felt that seems to absorb a lot of the pop-pops and it looks better than the black plastic air filter. Of course there are other options but give this a try. I'm not sure if spray paint comes in the same containers in Great Briton but any plastic can top that will fit over the air cleaner with space for padding will work.
Extending the exhaust pipe and installing the muffler at the end is always quieter than the kit pipe and muffler but requires some welding. Good luck. Let us know if you come up with anything new.
Tom
Hey Tom, I'm not sure of the quieting effect, but I like that painted and polished carb...nice touch!
 

taddthewadd

New Member
Mar 1, 2009
339
0
0
39
Visalia, California
So Tom, what you are saying is he felt between the paint cap and stock filter cover doesn't cover over or block the four holes. It just keeps the plastic from resinating. Am I getting it right?
 

DannyBOY

New Member
Jul 18, 2010
7
0
0
Manchester
is their anything else, i found out that you can put a bit of sugur in the petrol tank and it run quieter... not sure if it is true or not... could be a load of... :D
 

Hoeha

New Member
Jul 19, 2010
32
1
0
The Netherlands
I used to have a moped which had a clogged exhaust. Apart from the intake sound it only made a hissing sound from the exhaust. Mindyou, it only made 3 mph till i cleaned the exhaust. So if you don't mind running only 10% of your normal top speed....
 
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