Joe wrote:

Empty out the old gas, put in fresh ethanol-free gas with some Sea Foam.
Run it for 10 minutes, shut it off and let it sit over night.
See how it runs in the morning.

Thanks for that advice, which indicates that you're suggesting that the
wheezing is caused by clogged passageways, venturi's, and orifices, since
there are no injectors in such small engines.

Still, if it were clogged, then the stoichiometric ratio would be off from
14.5:7, but why the wheezing?

Why would a clogged passageway cause a speeding up and slowing down of the
engine, particularly engines that have a fixed throttle plate?