Onan generator too loud outside

[Full.Monte]

Our 4KW Onan Micro Quiet is too loud outside. Inside, it's fine. Does anyone make an aftermarket muffler that a guy could attach to the 1 1/4 inch exhaust tube while in camp? I'm sure the neighbors would appreciate it.

[The General]

Is the noise from the muffler or loose engine parts?
Did you check for exhaust leaks?


Steve

Quote:

Originally Posted by Full.Monte Our 4KW Onan Micro Quiet is too loud outside. Inside, it's fine. Does anyone make an aftermarket muffler that a guy could attach to the 1 1/4 inch exhaust tube while in camp? I'm sure the neighbors would appreciate it.

[W4MBG]

i put a gen(eric)-turi on mine, but most of the noise seems to be coming out from under the rv. i am considering lining the genny area with foam (keeping air flow in mind), and making a foam panel to put on the ground under the rv to see if that helps.

[Full.Monte]

Quote:

Originally Posted by The General Is the noise from the muffler or loose engine parts? Did you check for exhaust leaks? Steve

No, I haven't checked those things. The generator has only 33 hours on it, so it is pretty new. It's open to the atmosphere on the bottom. If I put an add-on muffler on the pipe, wouldn't that tell me right away if it works?

[W4MBG]

sure, but if it doesn't work, you have just bought a muffler that you didnt need.

[bluepill]

Quote:

Originally Posted by Full.Monte No, I haven't checked those things. The generator has only 33 hours on it, so it is pretty new. It's open to the atmosphere on the bottom. If I put an add-on muffler on the pipe, wouldn't that tell me right away if it works?

Good thought. I would check with the auto parts store, and make sure that they will take back the muffler if it doesn't work. Any pipe or muffler that you install a clamp on will probably NOT be returnable. Use silicone caulk to seal it, and you can remove it easilly later.

Another way to test it and see if it's exhaust noise or engine noise is to install an exhaust stack with the outlet up high.

For testing purposes only, you can use a 90 degree elbow and a ten foot pipe. Plastic plumbing pipe will work for a short time before it melts, and will tend to supress noise better than metal.

[Ed-Sommers]

I was once parked close to a guy that had the same problem. He used a ten foot metal hose (forgot what that stuff is called) that he temporarily attached to the exhaust, with the open end pointing in the least obtrusive direction. Dammed thing worked, and I appreciated it.

We were in a boondocking situation.

Ed

[Dunner]

I just tried both of the above last week. I made an adapter and used an 18" piece of flex exhaust pipe and 10' of pool hose. I routed it to the top intake vent in my car hauler trailer and tried running the genny inside. It was also sealed to the top vent with weather stripping. The exhaust tubing I.D. was 1.5" and I think it actually increased the noise due to the size of the pipe. Like it resonated or like a megaphone on a car or motorcycle.

I also made an adapter for a Briggs & Stratton muffler and there was maybe 1 DB of noise reduction.

I think with these Honda, Yamaha and Onan quiet generators, the noise that can still be heard is mechanical noise. I've read that people make boxes with air circulation and sound deadening material inside. I may look into that. I have a couple of AC and DC fans I could put on the box. Anybody know of an inexpensive sound deadening material?

[TitanicPilot]

Quote:

Originally Posted by Full.Monte No, I haven't checked those things. The generator has only 33 hours on it, so it is pretty new....

Your gen only has 33 hrs, but your coach is 7 years old, so the gen muffler or exhaust pipe could be rusted through. It only takes 2 minutes to check them out....

[HMXDave]

http://www.cumminsonan.com/www/pdf/rv/f-832.pdf See page 8. I added one of these to my rig and re-routed (added 4 feet or so) the tail pipe out the rear instead of the side. It made things a bit quieter for sure. Oh...and when it is said that the noise is reduced about 1 db....that's a fair amount. Sound energy is measure on a logarithmic scale and doubles every 4 db.

[Dunner]

"Muffler Benefits: Softens exhaust noise and can reduce sound levels
in some installations up to one dB(A)."

The human ear can only hear the difference in ~1 dB(A). When they say "Up to", that can vary. Just like looking at automobile cam specs. They can claim up to a 20% gain, but that's if you also add headers, port the heads, larger valves, higher compression, etc.

I have the "L" shaped pipe that comes down and out the side and would add the muffler if Onan didn't want my first born for it(Just a guess, heard they are not cheap).

[HMXDave]

Well..the muffler was 35 bucks...local shop bent up the pipe and supplied the clamps for another 20...took 15min of my time on my back...and the result was noticeable.

[Dunner]

I'm gonna check with auto parts or lawn mower parts or HD/Lowe's and see what they have. It's not loud to me, just don't want to upset anybody else. There may be some times when I want to run it early or late.

That's not too bad for a muffler at that size. I paid $110 for a 36" 4" in/out some years ago.