Fill the gas tank with water. But then the dead will still need earplugs because of all the foul language as you try starting it. <br /><br />I have an old Water Witch that had numerous holes in the exhaust manifold, but still had the pipe down into the water. I plugged the holes with pop rivets and it helped a lot. I doubt that would help in your case though. They're just loud clunky motors.
My buddy had a 5 hp Clinton which he used to bring along for fishing. A modern chain saw is probably quieter!!! We used to bug the heck out of him because it was so noisy. A few years later he bought a 4 hp Evinrude. We were all relieved!