Generator Muffler Question

[ancient-one]

My Coleman generator is powered by a 10 HP Tecumseh engine. The muffler on it is a joke as far as noise reduction goes. Is their any kind of a replacement muffler available that would be quieter? I know that I could solve a lot of the problem by buying a Honda generator but that is not going to happen. Any help appreciated.

 

[DeathGrip]

I remember my Granddad had a riding mower and thought it was to loud.He piped a Car muffler out the back.Danged thing was quiet as a mouse.I'd say it was an 8hp Briggs and think he said the muffler was for an Audi.This was in the early '70's.

My Granddad.

 

[DeathGrip]

My Dad has a generator that he uses just in case of an outage.

Luck has it he has used it more to tick off the neighbor.It's got a straight pipe.

My Dad.

 

[rburg]

I'm guessing its also motor noise, not just exhaust. Remember any back pressure will also hobble the engines power. Honda is quiet for a number of reasons, and the muffler is just one of them. You could try buying a new Honda muffler out of parts and getting someone to weld your exhaust pipe to the Honda. Or build an extension tail pipe a few feet long and add a second "resonator" muffler out at the end.

I'd guess (and its only a guess) that if Briggs or whatever could make their engines quieter with a better muffler, it would be an option.

 

[DeathGrip]

I'm guessing its also motor noise, not just exhaust. Remember any back pressure will also hobble the engines power. Honda is quiet for a number of reasons, and the muffler is just one of them. You could try buying a new Honda muffler out of parts and getting someone to weld your exhaust pipe to the Honda. Or build an extension tail pipe a few feet long and add a second "resonator" muffler out at the end.

I'd guess (and its only a guess) that if Briggs or whatever could make their engines quieter with a better muffler, it would be an option.

You are correct about the engine noise.You are also correct about back pressure and adding a secondary muffler.Once we get up to the car size it's just added quiet and not enough pressure to worry about.The straight pipe is bad for the engine and worse for the neighbors.

 

[mtelkhntr]

If we're using a generator around these parts on forest service land, it has to not only be a muffler but certified as a spark arrester. Lot's of options out there but depending on what you're using it for, they can get narrowed down real quick.
I once had a 5000KW gen with a honda engine on it but wanted to quiet it down some more so looked at other makes with the same engine with a better muffler. I think the honda dealer has a lock on parts and for what he wanted for the muffler, I could listen to a few more dB.

 

[enfield]

A better muffler will help, but it won't make it a Honda. A lot of noise is transmitted out of the engine mechanically and radiated by the castings (think drum head) and the muffler won't help it.

Situating the noisy generator inside of a hay bale enclosure will absorb some of the radiated noise and direct what's left upwards, away from ears.

I have a 5K Coleman, and I have my eye on a 2K Honda. Just waiting for some stimulus money . . .

 

[oldman45]

There is some websites that show how to install better exhaust systems on a gen set. One I used for my portable genset cost me about $30 and a couple hours of time. Now it is no louder than a car's motor at idle. It is more bulky to carry around but anyone nearby will not hear it.

The instructions are on the internet but simply I bought a new bracket that held the gen set muffler on. Took it to a hardware store and bough some pipe I could weld on to the bracket and step up in size with left me with about 8 inches sticking out of the generator. Took the bracket to a auto parts store and got an flexible exhaust pipe that I placed on the pipe with a hose clamp. Ran that to a auto muffler and I was in business. Just keep the muffler off the ground when using it and do not try moving it when it has been in use for a while.

 

[sar4937]

Part of the problem on the cheaper valve-in-block engines is that they fire the sparkplug every other stroke with a magneto. They do offer a cheap baffle that screws onto some of the mufflers (these mufflers are pre-drilled), it will cut down the noise somewhat. But even with quieter exhaust, alot of the noise will be mechanical fin ringing and vibration.

 

[ancient-one]

Thanks for your replys. After listening closer(not for long) it does seem as if a lot of the noise is coming from places other than the exhaust. I am checking out some of the do it yourself ideas.

 

[27145]

Could you use fiberglass muffler packing?

 

[JSR III]

Again, you need to be careful about changing back pressure. If the noise is bothering you alone, the you can fix that. If you are concerned about the neighbors, then that is more difficult.

enfield has the right idea and I had never thought about a hay bale enclosure. Hay or foam insulation, plywood can all be used to direct the sound or block the sound from your perspective.

When I participated in a few ham radio weekend events that required generator power, we merely placed plywood sheets on three side of the generator and directed the sound away. Worked just fine for us but not sure how the downwind neighbors liked it.

 

[squarles67]

I had a Coleman 5K with an 11 horse Tecumseh for many years. I tried many different methods to make it quieter with little success. As stated already most of it is engine noise. There used to be a "quiet" Tecumseh muffler available. It was almost $70 bucks back in the early 90's. Seemed worth it to me so I gave it a try, didn't make much difference. While it was just a little quieter it was still loud. Then I took a welding machine muffler and piped it in after the "quiet" muffler, dang thing was STILL loud. I just learned to live with it. Backpressure on those old valve in head motors is already pretty high so you're not going to make much difference with extra mufflers but you will have to adjust the mixture some to make it run good, as long as it has the high speed needle sticking out of the bottom of the carb just turn it slowly 'till it runs clean.

Some styrofoam wall board and duct tape to make a 3 sided box with the open side away from you will make more difference than anything else.

That thing ran forever but finally died in 2008 so I bought a new quieter generator.

 

[Gary]

I have a generator with an 8hp Briggs and Stratton engine. My brother added a muffler off of an old jeep. It helps some and doesn't seem to hurt the power output any. RV generators are a lot quieter. I think that they achieve this by using a bigger engine that runs at about 1/2 the RPM of the portable ones.

 

[ohiobuckeye]

I never found much of anything that will quiet the smaller single cylinder engines except distance. The styrofoam box with the open side turned away, sounds like the simplest, cheapest, and probably most effective. I have my emergency generator wired through a 80' piece of 8/3 wire that lets me either set it in the open garage door if it's raining or snowing, or roll it farther outside and close the garage door, if there is no precipitation.
I once had the bright idea to quiet my noisy old Briggs powered push lawn mower, so I took a couple of pipe elbows and nipples, and redirected the exhaust down through a hole I drilled in the mower deck. Quiet?...NO!...Different?...Absolutely!...With the exhaust directed onto the spinning blade and the sound echoing out of the big flared steel deck, it sounded like an entire squadron of Apache gunships hovering over my lawn....

 

[msinc]

I have a Honda and it ain't quiet at all. In fact I am in the process now of welding up a larger quieter muffler for it. All I can say is dont buy a Honda muffler and expect that to do much good. If what I build works good I will be glad to post photos and dimensions.

 

[Jim Kuykendall]

check the internet for sound supressing foam. Use in indoor shooting ranges. Glue it to the styrofoam walls you've built around the genset. Open cell foam is superior to closed cell(EPS) in sound abatement if you can find it. I'm facing the same problem with my 6500 Watt set. Thinking of piping the exhaust into a 20 gallon drum with fiberglass attached to the walls and baffled. An extra hole in the bottom of the drum allows for exiting gases.

 

[sar4937]

We used to use a dual density open cell foam with a layer of lead sandwiched in, about an inch thick to sound deaden RV genset compartments. I am not current on what is available today. Depending on the design of the compartment and location on the RV, it was usually a waste of money. The compartment had to take air in, and that's where the noise would leak out. The problem with boxing in your generator is cooling air for both the engine and generator, and fresh air for induction. You would be time and trouble ahead to sell your current genset and purchase one of the "designed to be quiet" invertor gensets currently available.

 

[enfield]

. . . When I participated in a few ham radio weekend events that required generator power, we merely placed plywood sheets on three side of the generator and directed the sound away. Worked just fine for us but not sure how the downwind neighbors liked it.

That's where I learned about the hay bale idea - we used them at Field Day (after the neighbors complained).