So, which one sounds better?

[Torino 14]

I have to agree with Dresden Guy.  I think it is all muffler. Pull the mufflers off and do a test.

[zeedubbya 18]

I get a huge smile on my face everytime I raise the throttle on the Onan so I vote Onan. Since I've never heard an Onan under 16 hp without two cylinders I like that classic Kohler sound pretty well too.

[KATO 115]

KOHLER for me  

[Ken B 3,134]

I have to agree with Dresden Guy.  I think it is all muffler. Pull the mufflers off and do a test.

It is what it is, they are both totally stock with stock mufflers. No excuses! lol!

[Ken B 3,134]

It looks as though the Kohler is winning this little contest quite handily after a few days of voting. I'm a little surprised, but not really! I know of a real nice 417-8 that is for sale that I'd like to have. The guy wants all the money for it, original owner as well. It has over 2300 hrs on its original Series II Kohler, but that is getting up there! The owner is honest and he says there is NO chance he ever left the key on for the hrs to build up. She does fire right up with no smoke and still runs nice and strong!

[JackC 617]

Both sound good in the videos.  Not sure that is the most accurate way to compare.

 

I have both, and from the seat, the ONAN wins on sound hands down.

 

Also, based on the smile test, when I start the ONAN and put it under load bigger smiles appear on my face compared to the Kohlers.

 

I had a guy help me mow my lawn once.  He is not a Wheel Horse guy.  He started with the C-175 and finished with the 520HC.  When he hopped off the 520HC, and without being asked, he said, "now that sounds like a real tractor".