Honda GCV160 5.5 how do I adjust the carbureta?

Defintely spark plug change. Had exactly the same problem. New plug sorted it out!
I know that sounds strange and all the symptoms point to fuel but........
Found a number of entries on other forums that had same problem and plug change as the solution.

Tim
May 2011

See if the gas cap valve is plugged. If it is it will not let air into the tank and creates a vaccume and doesn't let fuel enter the carburetor. Try running it without the gas cap on. See if that helps

Robb
April 2011

before you change any of the settings try fitting a new spark plug - worked for me having stripped down the carb etc!!

Chris C
June 2010