Winterizing Your Boat

[Gerry Zagorski]

Some tips for winter lay up on your boat.

OUTBOARDS :
Not much to do on outboards. You want to make certain you do the following things at a minimum…. Fog the engine, change the fluid in the gear case, flush the engine with fresh water and get some antifreeze in the engine block and treat your left over fuel with stabilizer.

• First thing to do is treat the fuel with stabilizer. You do this for 2 reasons.. 1) So condensation does not accumulate in your tank over the winter and 2) so the left over fuel in your engine does not varnish up and clog your carbs or fuel injection system.

Put the recommended amount of stabilizer in your fuel tank and run the engine long enough to make sure it gets through. In fact it’s a good idea to do this at your last fill up and run the boat in the water to make sure it mixes well….

• Next is the anti freeze. To do this you will need to have the engine muffs required to run your engine on the hose. What you want to do is get a 5-gallon bucket and fill it up with a gallon of antifreeze and a gallon of water. Put the muffs on the engine and run it on the hose to flush it out. Now stick the end of the hose coming from the muffs into the bucket. When you run the engine it will suck the antifreeze from the bucket into the engine so you are assured that all the water in the engine is treated so it won’t freeze and break something over the winter. While you doing this you should also be fogging the engine. Do not rev the engine while it’s on the hose. Doing so can ruin the water pump impeller.
• Fogging the engine protects the internal cylinder walls and pistons from rusting up over the winter. After you see antifreeze coming out of the return start the fogging process. You do this buy taking a can of fogging oil and spraying it into your engines air intake. Start of by spraying some in slowly with short bursts and then a steady spray until the engine chokes out or until the can is empty. If the motor does not choke out from the fog spray then shut the engine off when you run out of the fogging spray. Don’t start your engine up again after this or you will burn off the fog. Some people also like to take the spark plugs out, shoot some fog in the cylinders and crank the engine with out the spark plugs to make sure there is a good coating on the cylinder walls. If you do this make sure and put the plugs back in for the winter lay up since air is the enemy here….
• Now it’s time to change the fluid in the gear case. I like to do this before winter lay up because it gives you an opportunity to inspect the fluid. If there is water in the fluid you don’t want that water laying and rusting up your gear case all winter. Plus if you do find water in the fluid you’ll probably want to take your engine to a profession to find out where the leak is and get it fixed over the winter when it’s less expensive and your mechanic has the time to fix it. To change the fluid you’ll need to remove the bottom gear case oil screw which is a slotted screw head usually located in the lower unit about even with the prop shaft. To help the fluid flow better remove the top slotted screw head which will allow air to get into the drive and the fluid will drain faster. The old fluid should be dark brown or black. If it’s a milky white color then you have a leak somewhere and you should take the drive to be pressure tested by a professional. There are seals behind the prop shaft that is usually the culprit. They either wear or sometimes fishing line can get up in there and cause the seal to leak. If the fluid looks ok make sure and inspect the plastic washers around the screw heads you just took out. They are gaskets that seal the gear case to the screw head. As a matter of fact, it’s a good idea to replace these and the screws since these are inexpensive parts and it’s better to be safe the sorry later. Ok now you need to fill the gear case back up with fluid. You can do this one of 2 ways…By using toothpaste like tubes of fluid or my preference is to use the fluid that comes in a larger container with a pump and a hose with a fitting at the end which screws into the bottom screw hole. It’s a lot less messy then the tubes and is a lot easier as well. You want to pump enough fluid into the drive from the bottom screw hole so it comes out the top screw hole. Filling it from the bottom rather then to top displaces all the air in the drive with fluid. Now replace the top screw and your set…
• In addition to these things here are a few others

- Remove prop and grease shaft. If you don’t do this the prop can get stuck on the
shaft due to corrosion and make it very difficult to get the prop off. - Take batteries out and store inside and charge them occasionally a battery that is
not charged is subject to damaged from the cold.
- WD40 all linkage
- If you have any holding tanks drain them and put some of the pink RV type
anti freeze in them.
- If you have any sea cocks keep them open over the winter just in case there is water in them that could freeze up and cause damage

• Don’t change your fuel filter/.water separator till spring. It’s best to change that after you run a tank of fuel after winter lay up so any condensation that build up in the tank will get removed by the old filter.
• Same goes for spark plugs. Change them in the spring so the fogging oil will fowl the old plugs instead of the new ones.

NOW FOR INBOARDS AND I/Os

• Same basic things apply to I/O and inboards as outboards except :
• You need to take some extra precautions to make sure you get anti freeze into the engine block and risers. If you have a fresh water cooled system chances are you already have anti freeze on the fresh water side. Just make sure and check it to make sure it’s up to snuff by using one of the antifreeze testers you can buy in a car parts store. Now you need to flush the raw water side of the engine with fresh water. Depending on the set up you have you can either do this with muffs on the stern drive and run it on the hose (this is for I/Os that drawn raw water in from the stern drive) or in the case of most inboards and some I/Os you will need to find the raw water intake and run the hose to it. Most boats are plumbed with a hose hook up above the sea cock for the raw water intake so you can flush it.
• After you have flushed the engine you need to mix up the anti freeze in the bucket as explained above for outboards and get the anti freeze into the engine block and risers by either using the muffs on the I/O or running a hose from the raw water side into the bucket with the anti freeze.

- In the case of changing the drive fluid on and I/O is the same procedure as the outboard.

• You fog the engine the same way by spraying the fogging oil into the air intake.
• You want to change your engine oil and filter before winter lay up. The reason you do this is that old oil develops acids that can attack your engine bearings during winter lay up. Plus it’s one less thing you have to do in the spring.
• Try and seal up the air intake and intake and exhaust system. You can do this with duck tape or a plastic bag.

A Word of Caution …

• Many of the newer outboards and fuel injected I/Os and inboard manufacturers do not recommend you fog the engine through the air intake. This can cause damage to the fuel injection system. Many recommend you mix up a separate small batch of fuel with their fogging mix in it and run the boat on this mix prior to lay up. You should consult your owner’s manual to see what your specific manufacturer recommends.
• Winterizing your engine and gear case correctly is very important. If you’re not handy or not sure have a professional do it. It may cost a few bucks but it will save you a ton of money in the long run.