air filter silencer
I just rebuilt a yanmar 12 horse. I haven't even started it yet, I put it in the boat yesterday, but I won't start it until I put an air filter on it. That just seems like bad form to me. I am going to put a high flow after market car filter in place of the deteriorated silencer. I am sure with an air filter in place of the silencer it will be more silent. Also I am going to pull the air directly from the cabin so I get a colder flow as long as it doesn't make it too loud. I wouldn't worry about restricting air flow as long as you are using an automotive type, the foam type often used on lawnmowers and other single cylinder engines can and will restrict air flow. I'm pulling every trick in the book to try and get as much HP to the prop as possible from this little engine.