I was back at the lawn equipment parts store this morning, and the
counter guy also suggested a product called "Sea Foam," as something
that preserves gasoline and also does some clean out. Looked it up on
line. I'm going to buy a can at the local auto parts store.

Mower starts fine after I hooked the choke cable up to the right carb
control rod hole. Yes, I put it in the wrong hole. A girl told me that
once about 50 years ago, and then she slapped me...real hard. Nothing
bad happened this time, except the choke wasn't working. No slaps.