When laying up my 5hp two stroke Tohatsu, I stand it in a 5 gallon bucket of fresh water, without the
fuel line connected, and start it up. It runs for a few minutes, and if the bucket's pretty full, it doesn't make a mess. When it quits, that's it.
Four months later, it always starts on the second pull.
I don't do this on a regular basis, only when storing it for the
hurricane season.