What Happens If You Don't Winterize Your Outboard Motor?

“What if you don't winterize your outboard?” is a common question you don’t want to find out the answer to through firsthand experience, we can promise you that. 

Outboard not winterized milky oil

Finding out something went horribly wrong with your outboard at the start of the boating season because you didn’t take an hour to winterize it is not fun. Milky oil like what you see in the picture above is just the beginning. If you live in a climate with freezing temperatures, repairing freeze damage will be incredibly time-consuming, and could even result in having to replace the entire motor. 

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What is Winterizing an Outboard?

We’ve covered winterizing outboards and boats extensively, but if this is your first time here, it essentially means preparing your outboard for storage during the offseason

Outboard winterization products

That includes making sure there’s no water anywhere inside or outside the outboard, as water expands when it freezes, which can crack an engine block, destroy hoses and seep into the oil.

Winterizing an outboard takes about an hour to do, and whether you live in climates with freezing temperatures or not, you should do it anyway. Here are some things that could happen if you fail to winterize your outboard.

Engine Parts Cracking 

Failure to drain out freshwater and seawater alike from the outboard can crack and split open anything from wiring and hoses right down to the engine block itself.  

Outboard not winterized cracked engine block

As mentioned, water expands when it freezes, so if you don’t drain out the water as part of the winterization process, some busted cooling system and fuel system hoses could be the least of your problems.

Engine Corrosion 

Besides water damage, salt deposits and other acidic substances left in the engine due to lack of winterization can leave a path of destruction in the form of corrosion.

Outboard not winterized corrosion

Flushing out the engine to remove contaminants is an essential part of the winterization process to prevent corrosion of the engine during the storage period.

Dirty oil also has acidic properties that can break down the engine if left inside it during the off-season storage period. This is why changing both the engine oil and the gear lube is recommended as part of the winterization process, even if the outboard already had recent oil changes. 

Cleaning the outboard and spraying the interior of the engine with fogging oil before storing it during the offseason is also recommended to help prevent outboard corrosion.

Fuel System Problems

Leaving fuel inside the tank unused for an extended period of time will cause it to degrade, as well as create a separation phase in which the water/ethanol mixture separates from the gasoline and forms a layer on the bottom of the tank. 

Outboard not winterized fuel system

Filling the tank so there’s no room for water to build up is recommended during the winter storage period. However, if you don’t add fuel stabilizer to the tank as part of the winterization process, you risk having a tank full of unstable fuel, which can result in corrosion, gunk, and a slew of starting and idling problems

These are just a few unpleasant surprises that could happen if you don't winterize your outboard motor. By now you should know that it’s important to winterize it, but you also have to de-winterize it when boating season begins again.  

 

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