$131.46
268 ratingsSource: AmazonUse the specifications, images, available variations, fitment notes, and referenced part numbers to check this product against your application.
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155-1258 Cummins Power Generation Generator Exhaust MufflerCummins Power Generation is a world leader in the design and manufacture of power generation equipment, including PowerCommand standby and prime power systems.
Product facts
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Customer feedback
Source: Amazon. Imported marketplace feedback is shown for product research and is not a review of a purchase made on this website.
Richard –
Quieter than the old rotted out muffler. A bit longer muffler body. Overall length nearly the same. Did have to to a local muffler shop and have an reducing adapter since the inlet on this muffler is 1 1/2 inch. Thin metal. Unable to remove the moisture drain plug. In so tight I am worried I will damage the muffler. Saved money, as it is just a bit of $100 cheaper than the Generac muffler being marketed on Amazon. I painted the muffler with Utra High temp paint used on gas grills as the galzvinized finish on this muffler looks thin.UPDATE 08-13-2025 Over all this muffler is holding up. It is installed onto an 1989 Generac NP-52G gas generator installed in a compartment on my motorhome. The generator is ran and exercised under full load 15 minutes every week as required by the manufacturer’s service manual. So the muffle had a good amount of use. The zinc finish it came with is corroded off. I have had to paint it twice with high temp paint. In the photo is due for a paint touch up. I live in the deep south so the corrosion is not me driving on salted winter roads. Do note the exhaust nozzle point straight out. So if at an slight angle, rain water might get in. I added a angle tip to prevent that. The db noise level has not changed, pretty much the same as when it was brand new.
Customer –
Fit my Kohler generator perfect!!
Fat Joe –
Installed easily and is a perfect match replacement. Generator has never been so quiet.
Dave P –
Was not exact replacement for my style generator and had to revise the mounting method but has provided a sound reducing muffler for the generator.
inchgallo –
Exact match to my onan factory one,Seams well built,The sound is the sameGood purchse
Nick –
Made my Onan nice and quiet!!
Chris T –
The Onan muffler is a little larger diameter and a little longer than my original Generac muffler. It’s made a little better than the OEM Generac. Sound seems to be about the same as the OEM. It was a good price and shipped fast.
DG –
I have an ONAN BFA 4.0 generator on my RV and I bought this muffler to replace the old rusted out one. I noticed that the old muffler had the input tube more near the middle of the body, where this one has it on the end. I feel like it works better with this new design and it was easy to put on. It honestly took more time to remove the old muffler than it did to install this. I am very happy with the sound deadening and most importantly NO LEAKS! The old muffler had holes in the bottom where no one had drained it before and it rusted out- it would fill the cabin with co2. This new muffler also has the same drain plug as the original so be sure to use that every season to drain out any moisture that has built up over time.This is a great buy for anyone who has this kind of Onan generator.
bluespwr –
My old muffler blew the end-cap right off and was loud enough to wake the dead; annoying. This muffler is built well and brought the noise down to a manageable level. All generators are louder than we want, unless it is the inverter type. Plus, on class C motorhomes, a great deal of the time the height of the generator muffler is fairly high off the ground aiming for our ears anyway. I sprayed just a little high-heat gloss black spray paint on the tail-pipe end where it was basically uncoated steel, to prevent rust.
Richard Lemieux –
Installe on my RV 2800 Onan generator. Original from Onan is not made anymore and this muffler is a perfect substitute
Len –
Perfect replacement. Only tough part was removing the old rusted one. I needed to also replace the 2- 1 1/2″muffler clamps as they were also very rusty
Dan –
Works well but had to McGuiver since original Kohler RV generator had inlet and exhaust on same end of muffler.