The Best way to DeWinterize your Jet Ski

It is just as important to (de)winterize your jet ski or summerize the waverunner after it has sat for many months over the winter. This is true for simple 2 stroke skis as well as new 4 stroke muscle craft. By doing proper maintenance to your watercraft, this will ensure that it runs top-notch in the summer not leaving you stranded on the lake.

Inspect the Ski

Prior to starting your jet ski for the first time of the season, you will want to remove your seat and check your fuel and cooling lines for cracks or damage. Also, check to make sure they are properly secure and where they need to go. While in there, also check your electronic system for any melted wires, cables, or other damaged lines that could become a problem. Check your zip ties to make sure cables are properly routed and out of the way of any moving or hot parts such as the driveshaft or exhaust.

If the interior of your ski looks good, head to the back and check the impeller, ride plate, intake grate, reverse gate (if equipped) and any other moving parts for damage or wear and replace if you notice that anything does not look up to par for your jet ski season.

Put your Hull Plug(s) In

When you winterize your ski, you will pull your hull plugs so any water that is trapped inside can drain out. You will want to reinsert these in the spring so you don’t sink your ski.

Most watercraft have plugs in the back of the ski, but some older ski’s and standups do not. On my Honda, there are two plugs to reinstall. Make sure while reinstalling that the plugs and o ring gaskets are not brittle and do not need to be replaced with new ones.

If your plugs are not in the best of shape, make sure to replace them immediately as they can leak and sink your ski.

Check Fuel

If you didn’t add fuel stabilizer, you will want to drain your fuel tank and replace with new fuel. If you did use a stabilizer, make sure the fuel looks good and top off your ski for your next ride.

Check for Rust or Moisture

While in the engine compartment as well as under the ski, check for areas of moisture or rust. If there is moisture leftover from last season, this could mean that something could be corroded.

Check your electronic boxes to make sure they look good and are dry and seals are fitting properly. Also, check the spark plugs to make sure there is no moisture in there. If the ski was properly winterized, there should be no water to be found and you can move on.

Grease Driveshaft

The driveshaft will need to be greased to ensure proper free rotation throughout the season. Some skis have a little plastic cover to remove with wing nuts and have a grease fitting right in the driveshaft area, and some have a remote grease fitting. On the Superjet it is on the right rear of the engine and on my Honda F12X it is right under the third passenger’s seat.

Grease Steering Mechanism

The steering cable and components will need grease to ensure they do not get stuck while you are trying to maneuver your ski. There will be a cable that should have a grease point under the hood of the ski. Also, don’t forget to grease the moving parts at the rear of the ski. While greasing your steering, make sure to grease your reverse gate and handle to ensure proper function.

Change Oil

If you have a 4 stroke ski, and didn’t change your oil in the fall, now would be the time to change your oil. You will need an oil extractor, but this will pay for itself after one use. Make sure to change your filter as well. If you have a 2 stroke ski, you are in luck and can skip this step as you are injecting your oil, or have mixed gas.

Lube Throttle Cable and Choke

The throttle cable, as well as chock cable, will need to be lubricated to ensure they are operating properly. I use fogging oil to spray in the cable at the throttle of the ski as well as try and get it up the cable under the seat of the ski. Also, spray moving parts at the carburetors.

Next use fogging oil and do the same for the choke lever if equipped both on the lever as well as on the carburetors.

Battery Maintenance

You should have had your battery on a battery tender through the winter, but if not, give it a full charge from your battery charger of choice. If you have a lead acid wet battery, check to be sure your water levels are good. Now you will want to reinsert the battery in the ski and hook it up.

Check Fluids

Depending on your watercraft, check all of your fluids, oil, pump oil, gas, coolant, etc to make sure they are all topped off and good to go for the season.

Start the Waverunner

Now that your jetski is ready to rip as it is dewinterized, you will want to hook it up to your freshwater hose and run it out of the water for 5 minutes to ensure it is running properly and to burn out the fogging oil as well as antifreeze if used. Make sure to listen to your ski and that there is no weird noises or ticks.

Spark Plugs

If you have a 2 stroke ski, you will want to now change your spark plugs after all of the fogging oil is burned off from winter storage. If you have a 4 stroke, you also will want to reinsert your good plugs if you have a good and old set. In my ski, I use my old plugs to store over the winter with the fogging oil, and I have my new set for summer.

4 stroke skis plugs should last about 100 hours depending on the ski, but check your manual for replacement guidelines.

Anti-corrosion Spray

After you are done with your motor work, remove your seat or hood, and spray your engine, exhaust, or any metal parts in your hull with an anti-corrosion spray. This is our favorite spray as it works great to keep our engines looking brand new.

Wash the Ski

Now you will want to wash the ski and wax it to protect it from the UV rays in the sun. As jet skis are very small, this should take no time. Here is our favorite wax to use on our boats and jet ski’s.

Put on Registration

Now that your watercraft is cleaned and waxed, take some rubbing alcohol and hit the spots where your registration stickers go. Next, put your registration sticker on your boat and you are legal to ride.