Manufacturers of outboard engines, usually place a warning decal stating, if gasoline needs to be mixed with oil, what the proper ratio is. More at:http://tinyurl.com/nf2f8jv
A gasoline engine will have flexible electrical cables going to the spark plugs in the cylinders. Diesels have non-flexible steel tubes plumbed into each cylinder. Also, the scent of diesel fuel is different from that of gasoline. Diesel engines, when not warmed up, usually need a brief (10-30 second) warm-up for the glow plugs. This is usually the position on the ignition key switch, just shy of cranking the starter motor.
Not only will gasoline ruin a diesel engine, but diesel will mess up a gasoline engine as well — it won’t vaporize to make the explosive mixture with air needed to fire by spark. That mistake can be remedied, but in a G.O.O.D. situation, you won’t won’t have time to clean out the fuel system.