Stubby wrote:
My old Sears mower makes a lot of noise. Years ago I replaced the
"spark arrester" thinking it was a blown muffler. It's not. Now I'd
like to find a real muffler. Somebody out there must have solved this
problem.

Probably not, and some newer engines have a warning about modifying the
exhaust and voiding the warranty, something to do with proper back
pressure.

Honda makes a fairly quiet 4 stroke in comparison.