How do I make my simplicity tractor motor quieter?

[Jonny_The _Grass_Man]

My old Simplicity garden tractor has a Briggs and Stratton motor 191701 0121-01 6910201. It also has a sticker that says "when ordering parts use VS-99 to Engine type No."

It basically sounds like its running straight pipes but it has a muffler attached. Would ordering a replacement muffler quiet it down?

 

[Rivets]

If the third number you posted 6910201 is the engine code number, you have a unit which is approximately 53 years old. At that age there is a definite possibility that all the baffles in the muffler are gone. Changing the muffler will be a crap shoot, as to if it will reduce the noise. At the cost of a new muffler you will need to be a gambler to give it a try. Totally up to you and your better half.

 

[bertsmobile1]

Pull the muffler off and pack it with heavy duty pot scourers
Get some pipe, bend it down & weld to the end of the muffler this sends the pressure pulses down into the grass
From back then the exhaust port should be threaded with std water pipe thread.
If so you can put an extension pus an elbow a reducing boss fitted backwards to make the pipe bigger then fit a small motorcycle muffler
I once made a pair of standpipes with hot dog mufflers on them for a tow motor made from an old Troybuilt twin mower so it looked like a semi hauler
On the inside of the hood you can fit car hood sound dampening panels or rockwool ( not house insulating bats because they can catch fire ) .

 

[Jonny_The _Grass_Man]

I finally bought a new replacement muffler. I took off the old one and sure enough, every baffle was gone and I could look straight through it like a pipe.

I put the new muffler on and started her up. Very disappointed, not much quieter than when running the old muffler. The replacement muffler was only 9 dollars so not a big deal.

 

[bertsmobile1]

I would not expect any $ 9 muffler to work
Wholesale B & S mufflers start at $ 30 for a pepper pot style and go up to $ 200.
Mufflers specific to a mower brand are dearer sill.
Just did one on a 11 Y/O Z225 JD and it was $ 178 ( Aus ) Wholesale
That made a big difference
B & S made a lot of different mufflers for the same or similar engines with varying leels of quietening at various prices .

 

[Jonny_The _Grass_Man]

I would not expect any $ 9 muffler to work
Wholesale B & S mufflers start at $ 30 for a pepper pot style and go up to $ 200.
Mufflers specific to a mower brand are dearer sill.
Just did one on a 11 Y/O Z225 JD and it was $ 178 ( Aus ) Wholesale
That made a big difference
B & S made a lot of different mufflers for the same or similar engines with varying leels of quietening at various prices .

Where do I look? I plugged the part number into Amazon and they all looked the same.

 

[bertsmobile1]

What part number ?
the simplicity one or the B & S one
An engine that old should that a NPT threaded exhaust port
From memory a 190000 series is aroud 10 Hp and has a 0.75" or 1.0" NP thread
Basically it is a galvanised iron water pipe thread as previously mentioned
So you have a choice of a threaded muffler or a bolt on muffler
On the web page below are the B & S mufflers that should be able to eiter screw in or bolt on
The last item is a deflector that is screwed , or riveted over the outlet holes and pointed down to deflect the exhaust which makes the exhaust a lot quieter .
Now these are what was fitted to the cheapie mowers that used both the std B & S muffler and usually a B & S fuel tank strapped to the side of the engine .
If you click on the MORE box then you will see the B & S part numbers .
An muffler with "low-Tone' or "Hush Tone" wer the quieter ones
The page linked to below is of course from one of my Wholesalers in OZ but if you go to the Rotary, Stens Prime Line web pages and search Mufflers then you should bring up a similar page
After Market B & S Mufflers
Also on most of the sites is a "dealer Locator "
I know you will find this hard to believe but there are more places to shop than Scamazon & Eviplay
The muffler does not have to be exactly the same shape as the original but of course must be able to fit your mower
As you did no pos either your mower number or better stil a photo this is as good as I can go.
Generally a JD muffler will be quieter then the Murray mufflers followed by the generic B & S ones .