America's Definitive Marine Engine Magazine
One case history documented by Seattle-based Northern Lights/Lugger reveals how reverse-osmosis-generated water dissolved about a dozen temperature senders in a row before the warranty team finally figured out what the problem was. Here's something scary. There have been cases where cylinder liners eroded completely through in as few as 300-engine hours. But don't despair, there's a simple solution.
Bottled, distilled water from a food store or water supplier is recommended. Tap water often has a high mineral content and should never be used.