Instructables
Picture of muffle that noisy thing!
this instructable will show you how to make a quieter muffler for your go kart .or any other noisy contraption you have
 
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Step 1: Tools and materials

i'll start with safety .which is where we should all start

-SAFETY EQUIPMENT-

-welding mask
-welding gloves
-welding leathers
-leather work gloves
-safety glasses
-ear muffs or plugs

now that we've got the thumbs up from mr.safety

-TOOLS-

-welder
-grinder
-band saw
-drill and drill bits
-welding hammer
-wire brush
-tin snips or very strong (CRAFTSMAN) shears
-wrenches
-hammer
-marker/pen

these aren't needed but the make life easier

-OPTIONAL TOOLS-

-wire brush attachment for your drill or grinder
-spur bit
-drill press
-pneumatic air punch/flanger (compressor to power it)
-high temp spray paint

now the stuff that makes up the muffler

-MATERIALS-

-metal cylinder with a fairly large volume
-metal scrapes roughly the same thickness of cylinder walls
-1/2" threaded rod .several feet in length
-1/2" tie rod couplers
-1/2" nuts
-thin metal flashing (hazardous but galvanized will work)
-1" pipe .several feet in length



Step 2: Whats a muffler anyway?

before we start working you might want to check out this video to see the principal behind the muffler http://videos.howstuffworks.com/howstuffworks/4660-how-mufflers-work-video.htm

for my muffler body i used a small nitrogen bottle from a broken welder my dad picked up in someone's trash .as you can see even before i cut it it had seen better days .it was a good thickness (1/10 of an inch or so) so i didn't just blow holes in it when trying to weld .if you have a welder with more precise temperature settings you can of coarse use a something thinner .the other thing you will need is some pipe .for the tail pipe section .and you should have the muffler thats being replaced as you will need the exhaust manifold from it .on mine they were welded so i cut as closely to the muffler as possible to ensure i didn't have a lack of space issues later on

etcmn7 months ago

Thanks for the ible. Just looking to quiet my old lawn mower.

getthim5 years ago
what about a mini dirt bike muffler and for someone who can't wield ...yet.....
somebullcrap (author)  getthim5 years ago
are you asking my opinion ?
yes i am asking of your opinion, if you don't mind
somebullcrap (author)  getthim1 year ago
sorry i'm just now replying i didnt realize you had commented till now .anyway .it might be possible ,a screw in muffler made of gas pipe might work better since the muffler intended did screw in
Dannne113 years ago
what kind of motor are you using?
somebullcrap (author)  Dannne111 year ago
its a briggs and stratton
repguy20201 year ago
How did you build the cart? Nice muffler, BTW.
somebullcrap (author)  repguy20201 year ago
i didnt build the cart .it was originally bought from a store but was well past second had when i bought it
robot7973 years ago
do you has video?
Could i use an actual car muffler for this (have one laying around)?
LOUDER THE BETTER
general zee5 years ago
what size is the cylinder? i have a 5" x 12" fire extinguisher and i was wondering how big this was.
somebullcrap (author)  general zee5 years ago
the cylinder i used was 3 1/2" x 13"
ok, i figured it was about that size.
somebullcrap (author)  general zee5 years ago
yeah a fire extinguisher would make a great muffler housing .its lighter then the cylinder i used but not so light that it won't blow threw when welding .if i make another one i think i'll have to use your idea and use an old fire extinguisher
cool, i am making it for a snowblower, i need it to be quiet because i will be using it very early in the morning.
nibbler1256 years ago
i like my stuff loud but there are trails near my house and the people around the trails are mean and get mad whenever i ride so all my stuff has homemade silencers for them that are removable
Ya I was thinking about taking a pocketbike to a campsite for getting around and make a track system for the back and make-shift ski for the front (the hole camp is sandy) But to keep it down I may hafto make one of these for it
somebullcrap (author)  nibbler1256 years ago
well what are you waiting for? .i'm sure i'm not the only one who'd like to see that
skunkbait6 years ago
Any power loss from the exhaust-flow restriction (as opposed to a straight pipe)?
somebullcrap (author)  skunkbait6 years ago
yes .of coarse there is .but its so minor its not noticeable
I was just curious. My kid rides one with a straight pipe. Fortunately, we live in the country, so neighbors aren't a problem. Best I remember, some of the old dirt bikes used to actually run better with a little back pressure.
With 2-stroke motors the back pressure is essential for performance. You never want to run "straight" pipes. Without tappet valves, back pressure is needed to assist in keeping the air/fuel charge in the cylinder. It's not as important in a 4-stroke because the valve will close and reflect most of the back pressure. This motor looks like a 4-stroke (although I didn't see valve inspection covers), and if your having trouble accelerating "off the line" there should be an air/fuel mixture screw on the carb you can fiddle with to try to tune it. If the problems are across all throttle positions then you'd have to rejet the carbs. Probably not worth it for something your just horsing around on.
Yep, you're right. I was thinking 2-stroke. Engine in the pic looks like a Briggs.
chalky6 years ago
neat job mate:) but it would have been better if you'd have posted an audio clip of before/after modding.
uglymike6 years ago
Nice Project ! ! I love seeing people do this sort of thing, and the finished product looks almost, dare I say, professional. Now you're going to have to pretty up the rest of the cart to bring it up to the level of the muffler. Ha-Ha. Did you consider packing it with anything? Muffler repacking material, Steel wool etc... Seriously though, great instructable and great looking project.
somebullcrap (author)  uglymike6 years ago
thanks and yes i did think of trying that .and with the design of it i am still able to try it .if the curiosity gets the better of me .as it usual does .and i know .i hope to improve more on it
fiberglass would probably work just fine thats all thats in "glass pack" car mufflers