Exhaust/Stack Ideas

Ok, so i took it off and found out that the engine part is threaded. And i found a piece of pipe that would thread into it. What should i do next? (Unless I should just leave it like this... ) Its pretty loud too, how would i make it have a deeper roar to it instead of a loud popping sound?

You can only do so much with the sound. Small engines like these ain't going to sound like a 460 V8 gasser for sure. I found making the pipe bigger makes a deeper tone. Making a longer stack will also make it deeper, but it could be detrimental if you roll the thing over. Just try a bunch of ideas and see which one gives you the deepest tone.

for deeper louder volume a megaphone is best.

you have a threaded port. Go to a hardware store or any place that sells plumbing and heating supplies and for a few bucks, you can build a system that progressively gets larger as it extends. The longer and bigger the pipe the deeper it will get.


For maximum effect, a cheapo motorcyle megaphone from motovan will add a bit of flash and some nice tones.. They have turn out styles Rat tail styles, anything you could want for motorcycle atv side by side and sled parts. They are canadian, so shipping south may be an issue. but i find I can get their parts from any serious bike shop in town. And If you look, you can find some very economical deals on go kart, dune buggy, cycle , atv, stuff.

Sorry about the plug, but i love their catalogue.

I ran shorty pipes ( temporarily) on my 18HP twin murray - thing sounded just like a harley davidson motorcycle.

how i did mine

boggo, that setup is kinda like the one i was thinking of making. How does yours sound?

it sounded really good, nice thump to it but was abit loud being a black 11hp motor. lower revs should be fine though (i had mine screaming its head off). but everyone around my area likes it, so it did get alot of attention

Not a stack, but this is my exhaust. It's 1" from the block, stepped to 1 1/4" for 24" then stepped to 2" for another 20". It's got a good, low rumble at low RPMs, with a decent bark when wide open

That there is what is called a good looking tail pipe. Well supported, and well built. Not to mention good smooth flow.

Nice job

boggo wrote:

it sounded really good, nice thump to it but was abit loud being a black 11hp motor. lower revs should be fine though (i had mine screaming its head off). but everyone around my area likes it, so it did get alot of attention

Mine has an 11 hp, think that would be a problem if i run it wide open mostly?

AcreFarm wrote:

Not a stack, but this is my exhaust. It's 1" from the block, stepped to 1 1/4" for 24" then stepped to 2" for another 20". It's got a good, low rumble at low RPMs, with a decent bark when wide open

I dig that. Looks really professional lol

TennesseeCowboy wrote:

Mine has an 11 hp, think that would be a problem if i run it wide open mostly?

Unless you remove the governor, these things are built to run wide open all day long. Removing the governor will negate that. Over revving these engines can cause severe damage.

They are built to be best around 3000 to 3500 rpm depending on the engine. Some may even go as high as 4000.

Ours put up with ungoverned over revving just fine, but we also understand that we are reducing the life expectancy of the engine. In general, valve float will keep the RPMs down enough to prevent serious issues. For liability reasons, I would not recommend doing what we do though

Certain flathead flywheels have been known to explode, and cause some pretty severe injuries. I've had a flywheel come off after the threaded section broke on the crank, and the retaining nut disappeared. Some sanctioning bodies have outlawed rear engine riders due to exploding flywheels causing severe injuries.

I've heard that, and (other than modified engines) never seen any proof it happens. B&S would have to have the flywheels tested at a much higher RPM than stock for liability reasons. If you mod the engine to make the RPMs go past the natural ceiling that a stock engine has (like the racing people do), you would definitely have a point. The magnitude of a lawsuit facing B&S would be huge if a governor failed and the flywheel detonated. Would love to see someone get video of spinning one to the point of destruction to see what it would take.


Note: edited for clarity

...and like I said, I don't recommend anyone do what we do.

Lol thanks for the tips guys but thats totally not what i was asking..I was wondering if his pipe setup would be unbearably loud if i ran wide open all the time But thanks anyways:)

TennesseeCowboy wrote:

Lol thanks for the tips guys but thats totally not what i was asking..I was wondering if his pipe setup would be unbearably loud if i ran wide open all the time But thanks anyways:)

To answer your question is yes it would get loud after a while.

To answer your Q: Any kind of straight pipe is gonna be pretty loud at throttle.

Ahhh that sucks, I want it loud, just not destroying my ears loud haha

Where the exhaust exits will effect how loud it is for the operator. If you have a short stack that dumps around head-level it will be considerably louder for you than something that dumps below your head & out to the side, or out the back. My ATLT has no muffler at all, just the long pipe, and it is bearable for the operator. Not quiet... but definitely bearable.
I mow with an 11hp Murray that has a straight-thru tractor muffler which dumps below the left footrest. It's not bad for the operator, but it's pretty loud for anyone off to the side of it.

AcreFarm wrote:

Where the exhaust exits will effect how loud it is for the operator. If you have a short stack that dumps around head-level it will be considerably louder for you than something that dumps below your head & out to the side, or out the back. My ATLT has no muffler at all, just the long pipe, and it is bearable for the operator. Not quiet... but definitely bearable.
I mow with an 11hp Murray that has a straight-thru tractor muffler which dumps below the left footrest. It's not bad for the operator, but it's pretty loud for anyone off to the side of it.

Some good info here, what about slightly below head level and pointed forwards?

I think anything right at, or just above/below head-level is going to be pretty loud... If it is an open exhaust.
I've got a stack (straight-thru tractor muffler) on my Wheel Horse that ends above my head, and that's not too loud at all. But that wouldn't be a good option for a tractor that will be running thru brush and low-hanging branches.

AcreFarm wrote:

I think anything right at, or just above/below head-level is going to be pretty loud... If it is an open exhaust.
I've got a stack (straight-thru tractor muffler) on my Wheel Horse that ends above my head, and that's not too loud at all. But that wouldn't be a good option for a tractor that will be running thru brush and low-hanging branches.

i don't quite understand..did you use an actual tractor muffler?

On my regular mower, and my Wheel Horse I used tractor mufflers. My all terrain mower has no muffler, just the stepped tailpipe I made for it.

My regular tractors all have mufflers, yet some stock are loud as hell - i ran open shorty headers on the ex mod murray with a twin - thing was pretty loud , but it was temporary ( didnt want to burn a valve) .

The older briggs flatheads are threaded and use bolts to hold the mufflers on - my 82 has both. My 70 toro has a threaded setup on the 5HP - the only issue with that is its right near the clutch pedal - if my foot slips, itll burn my sneeker - need to find some sort of way to change it - it also has a small piece of metal welded to the chassis holding it up - im not sure if it was stock that way or someone changed it .

I should have said farm tractor mufflers. These are both straight thru, but you can get them with a center baffle