{"id":7121,"date":"2026-07-11T01:36:45","date_gmt":"2026-07-11T06:36:45","guid":{"rendered":"https:\/\/www.emanuals.com\/blog\/?p=7121"},"modified":"2026-09-09T08:37:13","modified_gmt":"2026-09-09T13:37:13","slug":"how-to-winterize-your-boat-complete-guide","status":"publish","type":"post","link":"https:\/\/www.emanuals.com\/blog\/how-to-winterize-your-boat-complete-guide\/","title":{"rendered":"How to Winterize Your Boat: A Complete Guide"},"content":{"rendered":"\n

Water expands about 9 percent when it freezes, and it does so with enough force to crack an engine block, split a manifold, or burst a water pump housing. That’s the entire reason winterization exists; a cracked block discovered in April can end up costing thousands of dollars to repair, while the winterization that prevents it costs an afternoon of work and some supplies. <\/p>\n\n\n\n

Freeze damage is also specifically excluded from most marine insurance policies when the boat wasn’t properly laid up, which makes this one of the least optional jobs in boat ownership.<\/p>\n\n\n\n

Just like you need to abide by winter storage best practices<\/a> for cars, boats also need their own process. Here’s the step-by-step guide to this process, in the order you’ll most likely work through it.<\/p>\n\n\n\n

Fuel System First<\/h2>\n\n\n\n

Fill the tank to about 95 percent to limit condensation, and add a marine fuel stabilizer at the dose on the bottle. Then run the engine for ten minutes or so, on the water or on muffs, so treated fuel reaches the carburetors or injectors. Ethanol-blended gas left untreated over a winter separates and gums the fuel system, and spring carburetor cleanings are the predictable result.<\/p>\n\n\n\n

Engine Oil And Gear Oil<\/h2>\n\n\n\n

Change the engine oil and filter before storage rather than after, because used oil carries acids and moisture that shouldn’t sit against bearings for four months. On sterndrives and outboards, drain and refill the lower unit gear oil too, and pay attention to what comes out: milky oil means water has passed a seal, and that seal needs attention before the boat goes back in, since water trapped in a gearcase can freeze and crack the housing.<\/p>\n\n\n\n

Protecting The Engine From Freeze<\/h2>\n\n\n\n
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This is the step where the procedure depends heavily on your exact engine, and where the factory manual earns its place.<\/p>\n\n\n\n