Re: Air filter or flame arrestor
While new to the forum (myself), I have spent years on the water and wanted to give a hand. You should NEVER remove the flame arrestor. It is too important in what it does, stop backfires from causing flames in your engine compartment. Most engines in a closed in area for I/O, and very little dust on the water as mentioned above so dust/dirt not a big problem. Had boats for over 25 years with just flame arrestor and still running great. This is a safety issue and required by the Coast Guard so leave it on. Happy (and safe) boating!
As for "marine" air filters, not familiar with them. I use stock flame arrestor.