So when I need an item like an alternator or starter, or valve cover or pan gaskets, is it ok to just go to the parts store and get parts for a 250 straight six or do I have to get marine specific parts for my 165 hp mercruiser?
Marine stuff is supposed to be ignition proof and fuel leak proof. Gasoline vapors are heavier than air. In a car, they just go out the bottom of the car body. Pretty hard with a boat. Result? Kaboom . . . That's also why you have a blower
It's also law. Plus if your boat catches fire or blows up and the insurance company finds non marine certified parts, no insurance. Items like water pumps are also different, bronze impellors to resist corrosion instead a thin steel stamping. Bronze core plugs for same reason.
Definitely get the marine electrical and fuel parts. Your life may depend on it. However, you can get them at NAPA. NAPA carries lots of marine parts but the counter guys usually don't know that. If you give them the right part number they will realize they can get the part for you, usually in a day or 2 if it's not on the shelf. I don't know if other real auto parts stores can do this or not.
gas vapors in a tight engine bay with little ventalation will ignite if you use auto parts - for all system parts that throw a spark
starter, alt, ignition, and such, use mariane only
