Merc 454:

[morris440]

Purchasing a 93 Envision boat. Motors are Mercruiser 454 365 HP version. Boat has been freshwater only up till now. Are these engines built for saltwater as well or must they be modified internally with salt-water specific materials to reduce corrosion?

[glassdave]

i have the same engines in my Scarab. i dont believe they did anything to the specifically for salt water. you will need to flush them well and maybe look into closed cooling.