Q: If I don’t have access to fresh water for flushing my outboard after each use, what’s the best way to avoid corrosion by salt water? Are any outboards more resistant than others?
Wallace Kaufman, via BoatingWorld.com
To combat corrosion, Yamaha uses three layers of paint on its engine parts and four layers on the exhaust system parts.
My kids used to hate me when they’d ask something like, “What’s four plus seven? Eleven?” And I’d reply, “It depends. Are we dealing with metrics or ‘base 10’ or what?” I always left wiggle-room. Now, as to flushing…
When Suzuki first brought its engines to the U.S. in 1978, it tested them in Florida, where, the manufacturer found, the salt water made the Sea of Japan look like a freshwater pond. Manufacturers have tried various methods to reduce corrosion through bonding straps, special cooling passage sealants, anodes and the like. No matter how good the protection, it ultimately comes down to how much it will cost, and what the consumer is willing to pay. So, looking at that history, various models are better suited for protection at different stages of manufacturing. (See. “It depends.”) I would say two things here: First, BRP/Evinrude probably has the best internal corrosion protection. Suzuki and Yamaha have found problems in various specific models (with Merc using Yamaha powerheads and BRP using earlier Suzuki engines, the problems cross-pollinated), but all the manufacturers are dealing with it in their own way. Here on the Chesapeake, watermen may, or may not, flush their work engines once in a five-year lifetime, or thousands of hours, which leads me to believe that continual use of the engine is the ultimate right answer! — GM