In fact, if it's got carbs and either magneto or stator ignition, will will continue to run until you turn it off - that actually shorts the ignition. Magneto and stator ignitions will fire regardless of external power source. That is why you can pull start many outboards even with a dead battery. I have actually pull started a 115 before - but I would NOT recommend it as a routine method...
Obviously this will not work on electronic fuel injection - got to have juice for that!
This also reminds us that it is important to be careful turning over an outboard engine - even with the battery disconnected. You can start an outboard by turning it over if the spark plugs are connected and there is fuel in the carbs. Only a turn or two is needed for the engine to fire.
