Exactly, no filter on my generator.
Only if it has a pressurized oil system. My 15hp walk behind mower with a Kawasaki engine has an oil filter. My 8hp Ariens snowblower doesn’t.
I will bet your Ariens still has a pressurized oil system even without a filter
I have torn 5 hp Briggs and Tecumsah (sp?) filterless lawn mower engines apart and found each have oil pumps and pressurized systems. Piston pumps that are run off the crank.