How To Winterize A Jet Boat (4 Easy Steps)

Winterizing your jet boat is key to protecting the engine during cold weather.

Otherwise, you will experience damage from freezing and expanding water and bad fuel.

Fortunately, it is not difficult; all you need is the know-how!

How to Winterize Your Jet Boat:

There are four steps to winterizing your jet boat. You need to fill your tank and stabilize the fuel; flush all the water out of the engine; fog and lubricate the engine; and finally, remove the batteries.

1. Stabilize the Fuel

It is important to fill the tanks if you will winterize, which prevents condensation from forming above the fuel.

Condensation will mix water into the fuel and ruin it. The fuel, therefore, needs to be treated with a fuel stabilizer to preserve it over the time it sits.

Fuel that is not stabilized will deteriorate and gum up your engine!

There are various stabilizers on the market, so make sure you follow the directions for the one you have chosen, as they differ from brand to brand.

Add too much, and the gas will gum up; too little, and it will not stabilize. Sta-Bil is a popular choice.

After filling the tank, run the engine for five minutes to get the stabilizer thoroughly mixed with the fuel. This also gets the stabilizer into the fuel lines and engine parts like the cylinders.

It is also a good idea to use a stabilizer if you are not going to use your boat for several weeks.

You don’t want it deteriorating while sitting idle.

2. Flush the Engine

All engines use water to cool them as they run. Dirt and salt build up over time, and they need to be removed for winterization.

Connect the hose to the engine’s flush port. Fire up the engine and then begin flushing.

If you start flushing before turning on the engine, you will flood it!

After five minutes or so, turn off the water. Then run the engine at 4-5K rpm for a few seconds (five or so). This blows out any excess water.

Some people recommend stopping this stage here, as your system is now free of dirt and salt. But this will still leave some water lingering in the system unless you blow compressed air into it.

So, it is a better idea to now repeat this entire process using marine antifreeze.

Doing so assures that any moisture lingering in your system is actually antifreeze, and it will not cause any harm as the temperatures get low.

3. Fog the Engine

Fogging the engine is essential, as there are still water droplets on the engine’s interior walls after flushing.

Fogging oil is a lubricant, so that will protect your engine against this water.

You can do this process at the same time you are flushing your engines to save time.

First, you need to remove the filter from in front of the air intake. As the engine is idling, spray fogging oil into the intake in small bursts. If you spray it too long and quickly, the engine will cut off before it is fully lubricated.

The engine will sputter, and white smoke will come from the exhaust as you are doing this step; this is good. It means the engine is being coated with the lubricant.

After at least fifteen seconds of this, spray enough fogger into the engine to shut it off. Repeat the process on the second engine if you have one. Now the insides of the engine are properly lubricated.

After the engine cools (and you have ended the flushing process, if doing both), remove the spark plugs. Spray fogger into each one, and then tap the engine’s ignition; you do not want to start it, turn it over to get the lubricant inside the cylinder.

Inspect the plugs for any carbonization and replace them, if necessary. Then put the spark plugs back in place.

Finally, it is an excellent idea to spray the wirings in the engine bay with WD-40 or a similar lubricant. This will protect them from corrosion over the winter or other idle time.

4. Remove the Batteries

This is an easily forgotten step but still necessary.

Batteries can be drained while being hooked up to radios, clocks, and bilge pumps, even if they are not in use!

This is the easiest step! Remove the negative terminal and then the positive. Take the battery out and check it for corrosion on the posts and the terminals as well.

Clean them if necessary, using a stiff-bristled brush and a battery cleaner (some people use cols as it is acidic). Coat the terminals with grease to prevent corrosion.

Then check the battery for any problems like cracks in the casing or a low water level.

Now you are ready to store it for the winter:

  1. Place it on a rubberized surface in case of drainage.
  2. You may put a trickle charger on it periodically so it does not lose its charge.
  3. After this, it is time to clean your boat and put on your protective cover.
  4. Placing an anti-mildew bucket or device inside is also a good idea.
  5. Make sure there is no water between the hulls, as well, as that can freeze and cause cracks in the fiberglass.

Do You Always Need to Winterize a Jet Boat?

If the temperature in your region never gets close to freezing, and you are using the boat constantly, you do not need to winterize.

But if you live in an area where the winter gets cold, or your jet boat will be sitting idle for several months, you need to winterize.

Otherwise, the water in the engine (used to cool it during use) will expand in the cold and damage the metal.

How Much Time Does it take to Winterize a Jet Boat?

Including filling the tanks, the first time you perform the whole operation may take you close to two hours, depending on the individual boat and whether you combine steps two and three above.

With experience, this will take less than an hour.

When is it Recommended to Winterize the Boat?

When the temperature starts to dip toward 40 degrees Fahrenheit at night, or you will not be using the boat for several months, you should winterize it.

You do not want to wait until the temperatures have already gotten to freezing, as damage may have already been done.

How Much Does it Cost to Winterize a Jet Boat?

The cost of having a professional winterize your boat varies based on its size but seems to average around $300, though it can cost a lot more.

This is before any storage costs are figured in. Doing it yourself requires buying the flushing system, stabilizer, fogging oil, and antifreeze.

You can find these products on websites for around $100.

Your investigations as you winterize may demonstrate that you need to replace the battery or spark plugs, but this is not a figured cost of the winterization process.

Final Thoughts:

Water freezing in the engine of your jet boat will cause irreparable damage, as the metal cracks with the expanding ice.

Winterization is thus a necessary step, and it is important to do it right.

Knowing how to winterize your jet boat properly will prepare it for both the cold and the upcoming season, as well as the years to come.

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