[Elfsea] OT - need helpful suggestions-quick!

[Vicki Marsh]

Xene here:

My darling helpful son, while trying to mow the lawn, put the gasoline that
had two-cycle oil added to it into the lawn mower.  Now, this gasoline
wasn't marked that it had two-cycle oil, but Llywelyn and I knew about it.
We forgot to tell Arnbjorn.

The gasoline is at least a year old, too.  Yes, we know we should have
disposed of it by now, but.....

Fortunately, the lawn mower has not been started since Arnbjorn put this
old, oily gasoline in it, and we have drained all of it out that we can get
out. Right now, I'm letting the stuff evaporate with the cover off.

Now, what can I do to keep the carburetor from gumming up with this stuff?
Would adding a higher octane gasoline help?  Should I rinse it out with
regular gas, drain it, then re-fill and have a go at it?

Any of you mechanic-type people out there got any ideas?

Xene (who may still smell like petroleum by-products at Queen's tomorrow.)