Easy to check the output.
Start the engine and run for a minute and shut it off. That will make sure the carb is full and will start right up.
Disconnect the fuel line from the carb and slip a piece of gas hose over the end. Put the other end of the hose into a plastic gallon bottle. (not balanced on the fender)
Check a watch and start the engine. When the engine stops check the time and see how much is in the bottle.
