Too embarrassed to post a picture, but forgot to drain my mower's tank last fall. Of course, it's now surging like mad at all throttle positions, and won't idle at all. Runs pretty smooth on full choke
Workbench is now home to a fully dissembled carburetor. With luck, plenty of cleaner and compressed air will have the mower up and running.
Worse case is $25 for a new one <sigh>.