Duromax generator to muffler

[nancyk]

I purchased a Duromax XP13000HX a few months ago when the generator my husband purchased for Y2K finally decided it would not generate electricity. Ran fine but no juice. This new one is in place(stationary), connected to a large propane tank, we attempted to start it, turns out for running on propane you need a different spark plug. I have the plug now but it is not installed. The electrician tried to connect the generator exhaust to the existing muffler system but the end of the flexible steel pipe and the outlet of the generator are the same size(he tried to get a metal connector but has not found one yet). Currently the exhaust has a small cover on it, with a filter(first picture, on the right side, to the left of the upright), I assume so no pests can go back into the exhaust area. Any suggestions how to simply connect the two ends? I have contacted Duromax and sent pictures(their request), they say modifications to the exhaust may void the warranty.
Nancy

 

[Engineer42]

I purchased a Duromax XP13000HX a few months ago when the generator my husband purchased for Y2K finally decided it would not generate electricity. Ran fine but no juice. This new one is in place(stationary), connected to a large propane tank, we attempted to start it, turns out for running on propane you need a different spark plug. I have the plug now but it is not installed. The electrician tried to connect the generator exhaust to the existing muffler system but the end of the flexible steel pipe and the outlet of the generator are the same size(he tried to get a metal connector but has not found one yet). Currently the exhaust has a small cover on it, with a filter, I assume so no pests can go back into the exhaust area. Any suggestions how to simply connect the two ends? I have contacted Duromax and sent pictures(their request), they say modifications to the exhaust may void the warranty.
Nancy

Is that in your crawl space?

 

[LouNY]

You don't say the OD of your flexible lines but exhaust clamps are available in many sizes;

 

[nancyk]

No, it is under the back porch, full stand up space. A deck was built to hold the generator and the area under the porch was covered, so the generator does not get rained on. Lots of area to work in, can send more pictures if needed.
OD of exhaust with cover is one inch and 1/8, OD of flexible pipe is one inch. I assume if I get the coupler/clamp the cover and filter of the exhaust will be removed.

 

[Engineer42]

No, it is under the back porch, full stand up space. A deck was built to hold the generator and the area under the porch was covered, so the generator does not get rained on. Lots of area to work in, can send more pictures if needed.
Looks like I need to measure OD of exhaust and of flexible pipe.

Whew. Ok. Just checking.

 

[LouNY]

I'd like to see more clearance to combustibles for your exhaust or at least some shielding.

 

[nancyk]

the set-up.

 

[ponytug]

No, it is under the back porch, full stand up space. A deck was built to hold the generator and the area under the porch was covered, so the generator does not get rained on. Lots of area to work in, can send more pictures if needed.
OD of exhaust with cover is one inch and 1/8, OD of flexible pipe is one inch. I assume if I get the coupler/clamp the cover and filter of the exhaust will be removed.

Many auto parts stores stock the sort of reducers and adapters that you want, though around here the stock of one inch +/- can be thin. Generally though, from a generator, you want a larger pipe than the engine exhaust. I would get some larger ID flex pipe, and do any adapting on the add-on muffler.

The mesh is probably a spark arresting mesh, required on most gasoline generators these days. It does bear checking periodically to make sure it hasn't clogged with rust or carbon.

Do you need the extra exhaust pipe if it is open to the outside?

All the best,

Peter

 

[DarkBlack]

Looks to me like you are attempting to connect the new generator’s muffler to your old pipe/muffler plumbing. You’ll end up with two mufflers in series, unless I’m seeing it wrong. That could be more resistance to air flow than optimum. Probably the most simple solution, is to ditch your old hose/pipe setup with that rusty muffler, and replace it to the wall with a single piece of flexible pipe sized to the new muffler, and adapt it to size as needed, at the wall

 

[nancyk]

"

​

​

"probably a spark arresting mesh" that makes sense.

"Looks to me like you are attempting to connect the new generator’s muffler" new generator does not have a muffler that I know of.
"Do you need the extra exhaust pipe if it is open to the outside"
"Probably the most simple solution, is to ditch your old hose/pipe setup with that rusty muffler, and replace it to the wall with a single piece of flexible pipe sized to the new muffler, and adapt it to size as needed, at the wall" that also sounds doable.

I do not feel the need to give too much information. But. Since my husband passed and I decided to keep the property, a lot of what I do is repairing/replacing/updating what he did years ago. I have 2 Stihl 009 chainsaws(at least 25 years old) that I repair as needed, I use them easily and he said they were great chainsaws.
I pretty much know what I know and realize what I do not know. If I can easily replicate what was done, and worked well, I will do that. When this 25 year old generator died, I was hoping to just put another one in its place. Now the rest is fine-tuning. I am out-of-my element here though am somewhat knowledgeable(I do have a licensed electrician friend who comes by when he has time to help with the wiring). As to needing the exhaust pipe to the outside, that is what is there. Possibly it is not needed. That is why I am posting on this forum. I do realize it is a lot to ask, but any input is truly appreciated. I have reached out to Duromax, they said they do offer a muffler but have really not gotten back with me.
I assume the muffler was put there years ago for noise cancelling. And possibly to put fumes outside the enclosed area it is in. If the generator is not too noisy( it has not been started yet), could I connect a flexible pipe to the generators exhaust outlet and run that through the outside wall, without going through a muffler?

 

[grsthegreat]

On some older generators ive had in the past i was able to remove the large “muffler” they provide and simply install a flex pipe on the remaining stub and ran it thru a car muffler to deaden the noise. I did this for 15 years until i installed the whole house generator.

 

[nancyk]

I assume there is NOT a muffler that came with this generator. Could I just put flex pipe on the "stub" without a muffler? By looking at the current setup I do not believe hooking up a new muffler to a new flexpipe would be out of the question, especially with help from my electrician friend and his helper.

 

[grsthegreat]

My portable has a kind of a muffler. More like a sound baffle. I know it hooks onto a pipe with a clamp. Not sure of the duromax. It does muffle the sould compared to if it wasnt there, but ill bet its more of a flame arrester by design.

 

[5030]

Your old genny that quit producing electricity, all that was wrong with it was the generator head lost it's residual magnetism which is why you must 'exercise' any genny under load once in a while whether you need it or not. Nice thing about a standby genset, they exercise on a regular basis without any input on your part. Easy to restore the residual magnetism in any genny. You just full field it and I bet your electrician friend knows all about that.

 

[B7510HSD]

There is a muffler on this Generator all you need is the flex pipe to route the fumes outside! take off the short piece already on the generator and buy a longer one that will reach the wall.(napa)

 

[nancyk]

"must 'exercise' any genny under load once in a while "
the previous generator was turned on and run for 20 minutes every month since we've had it. I did attempt to "flash the field", had no success.

​

B7510HSD- how do you know there is a muffler on this generator? that would be great if all I required was a piece of flex pipe to go outside. I should remove the spark arrestor screen and put the pipe directly on the stub,w/a clamp? The screen is on there pretty tight right now but has been off when we attempted to attach the current piping,
Well, look what I just found. "the DuroMax XP13000HX generator has an oversized noise reducing muffler with a built-in spark arrestor. The muffler helps the generator operate quietly and smoothly."

 

[ponytug]

"must 'exercise' any genny under load once in a while "
the previous generator was turned on and run for 20 minutes every month since we've had it. I did attempt to "flash the field", had no success.

​

B7510HSD- how do you know there is a muffler on this generator? that would be great if all I required was a piece of flex pipe to go outside. I should remove the spark arrestor screen and put the pipe directly on the stub,w/a clamp? The screen is on there pretty tight right now but has been off when we attempted to attach the current piping,
Well, look what I just found. "the DuroMax XP13000HX generator has an oversized noise reducing muffler with a built-in spark arrestor. The muffler helps the generator operate quietly and smoothly."

First, I think that the manual for this generator is one of the best that I have seen, and has a number of important tips for starting it, break in time (6-8hrs, no more than 50% load, then change the oil, and recommending synthetic oil thereafter).

https://cdn.shopify.com/s/files/1/0613/1168/0689/files/XP13000DX_manual_revised_06162022_WEB.pdf?v=1656093569

I've used similar generators as well, and I agree with @B7510HSD that your generator has a muffler. It is visible in one of your photos, the silver item to which your spark arrestor is attached.
https://cdn.shopify.com/s/files/1/0613/1168/0689/files/XP7HP_XP16HP_manual.pdf?v=1646696282 (Part #18)

Again, the manual is an extremely good one, with lots of great advice on running, and maintaining the generator.

Personally, I would not go removing the spark arrestor. Generators these days are tuned and optimized nine ways to Sunday, and I would not make any bets that the generator will run better without it. The bet I would make is that the generator will run a little louder without it.

I have to comment that I'm personally not that wild about running a generator in a space surrounded by wood, and partially enclosed. I understand that you have done this for some time, but I would point out the fire risk.

All the best,

Peter

 

[ssgp2]

I have the same generator. Yours does have a muffler with spark arrestor. Ditch the existing piping and muffler you have from the old setup and use something like this with a stainless clamp.
https://www.amazon.com/FORTLUFT-Gal...=d2lkZ2V0TmFtZT1zcF9zZWFyY2hfdGhlbWF0aWM&th=1

 

[B7510HSD]

I installed the same unit and it does have a muffler.

 

[DarkBlack]

If you replace your old three piece flex-pipe, muffler setup with a new single flex, as some of us have suggested, I would definitely remove the spark arrestor before connecting your new flex to the engine muffler, if it was mine.
Your long length of flex should make it virtually unnecessary, especially if your wall exit area is non-combustible.
If you still want to use it, I would relocate it to the outside exit pipe where you can inspect, and easily clean it if necessary.
If you bury it under your new flex tubing and clamps, you’re almost guaranteed to forget it’s there, and you’ll likely run into future engine performance issues