PART TWO - Detail & Failure
The Sonoduct never sold in Australia - certainly not on any AUS made lawnmower,
and no evidence exists of any imported machines. The reason is probably pretty
simply ... it didn't take-off in the homeland either.

In a 1980s Briggs publication, a brief story is told [with accompanying image]:

" the SonoDuct, a totally enclosed, quiet engine, was in the experimental stage
in 1958 when examined by Ed Oehler, Hugh Brown, Bob Harkness and Jack Ebershoff.
The SonoDuct was unique in that the flywheel was located under the unit rather
than on top. It did go into production, but acceptance was hampered by the fact
that a large, odd-shaped hole was required on the deck to install the engine."

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SOURCE: https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/60454/BRIGGS_&_STRATTON_-_Histor.html
p.s. Who would use a suitcase on mower deck styling?

I have found some extra information from a private website, but I have
been unable to verify some of the comments:

[Linked Image]
[Linked Image]

TO BE CONTINUED ...