Jetting Resources

One of the key aspects to keeping your outboard jet engine in peak condition all season long, is how it was stored over the cold winter season. There is more to getting your boat ready for winter storage than just throwing a cover over it. As a rule of thumb, anytime your craft is going to sit for 60 days or more, it should be conditioned for storage or better known as winterized. Being that an outboard jet engine does not contain gear oil in the lower unit as a prop drive does, many make the mistake that it does not need conditioning before winter storage.  Skipping this crucial step often results in significant expense due to mechanical problems once Spring arrives. If jet boat owners knew how easy and inexpensive it is to prepare their crafts for storage, most would take their boats and engines through the steps.

Getting Started:

When it comes to gathering the tools and marine supplies required for winterizing your jet boat, you’ll more than likely have to make a short, inexpensive trip to the local marine shop. Purchase a bottle of fuel conditioner, a can of engine fogger and an engine flushing unit if you do not already have one.  The cost for a flushing unit is only about five dollars. It is used in conjunction with a garden hose to supply water to cool the engine as it runs. These units are required anytime the engine is run out of the water.  The only tools required for winterizing the boat are basic, an adjustable wrench, spark plug wrench, screwdriver, grease gun, and a garden hose.

Fuel Stabilizer / Conditioner:  

The first step is to add the recommended amount of fuel conditioner into your gas tank. The ratio of conditioner to gallonsof fuel is listed on the bottle, use the amount recommended for the amount of fuel left in the tank. This additive stabilizes the fuel for long term storage, dissolves harmful deposits in the tank,  helps to prevent condensation and protects the fuel lines from freezing. It is best to add the conditioner and then some additional fuel, this assists in mixing the additive. A full tank is not required or recommended, it is always best to have room to add fresh fuel come Spring. Next, you will want to get the stabilizer into the fuel lines and engine. To do this, the engine must be run for ten to fifteen minutes. The engine must never be run without ample water to cool it. This is where the flushing unit and garden hose come into use.  

First use the adjustable wrench to remove the bolt located between the grease fitting for the bearing and the lube hose coupling. Thread the flushing unit into place and attach the garden hose. Turn on the water and start the engine. Leave the engine run on fast idle for at least ten minutes, this process stabilizes the entire fuel system. Once the engine runs for ten minutes, it’s time to fog the engine.

Fogging Down the Engine:

For safety reasons, shut the engine off first and then remove the engine cover. Next unfasten the screws that hold the air box in place. This is done to provide full access to each of the carburetors. It is important that you are in a well ventilated area as this step does just as it  suggests, the smoke fogs up the area fairly well. With the water running, start the engine again.

The process of fogging the engine might better be known as bogging the engine. The object is to spray the engine fog directly into each carburetor until the engine stalls. Each cylinder will shut down after about 5 to 10 seconds of direct spray. By doing it this way, the fogging spray reaches the pistons, rings and cylinders. Once there, it coats and protects them from corrosion. during the off season. Turn the ignition to the off position and disconnect the garden hose and flushing unit. Replace the flush bolt and fasten the air box back into place.

With the socket wrench, remove each spark plug and spray the engine fog liberally into the top of each cylinder. After all the spark plugs are out and each cylinder sprayed, briefly turn the engine over a few times to make sure the fogging oil lubricates and coats cylinder walls. Thread and tighten each of the spark plugs and connect the wire boots. The engine cover can now be replaced.

Fogging the engine is an absolute must for any outboard that spends time in salt water. The fogging storage oil coats and protects the engine internal workings from rust and corrosion. This will add longevity to any outboard.

Reducing Moisture:

To remove as much of the water and moisture from the jet pump and bell housing, fully tilt the engine back a few times, this will empty most of the water left in the housing. While there will still likely be some water left, the object is to remove enough of the water so that when it freezes, it has ample area to expand without causing any damage. Next, use a quality marine grade grease and completely lubricate the main bearing until the new grease purges all the moisture from around the bearing. Pump a heavy dose of grease until the discharge coming out of the hose coupling is clean and free of and water.  Wipe off the excess and reconnect the lube hose. This will protect the main bearing and seals during the harsh winter elements.

While the grease gun is handy, take the time to distribute fresh lubrication into all the grease fittings, also known as zerks. After shooting grease into the steering housing, be sure to move the engine all the way left and  right to disperse fresh grease along the slide arm.

Once the engine and fuel system are adiquately conditioned for storage, move the attention to the hull. Pull the transom plug, clean  and completely drain all of the livewells. If the livewells were heavely used, it might be a good idea to prop them open a few inches to allow some air to flow. Remove all gear from the storage boxes, anything that might rust or mildew through the temperature fluctuations should be stored inside.

All safety equipment should be removed and inspected. First aid kits should be gone over  and new supplies added. Wearable PFD’s and throw devices should be inspected for damage. Check the fire extinguisher and make sure the pressure gauge displays that it is still fully charged. All emergency flares will have an expiration date posted on them, make sure these dates do not expire prior to the end of the next boating season. If they do, replace them. If you have a weather radio or flashlight, be sure to remove the batteries to prevent corrosion or damage. Replace them with fresh batteries when the boating season starts again.

Fully charge and then remove the starting and trolling batteries. Marine batteries are best stored inside during the wintermonths to avoid the extreme temperature fluctuations that will shorten their charging life. Any electronics that have LCD Liquid Crystal Displays should be removed. Even though they are sealed for marine applications, these are very susceptible to condensation from temperature cycling and are best store in a dry place. If removing the electronics requires complicated unwiring, be sure time is taken to label all unharnessed wires with a permanent marker.

As a final step, take the time to wash the river debris marks off the hull and engine. Be sure to store the engine in the down or running position. Cover the engine and the hull with a good fabric cover to allow it to breathe. A cover will keep the elements off the interior and protect it from the damage often caused by the sun’s rays. Raise the trailer jack so that the bow of the boat is higher than the stern to allow for good drainage and the craft is now conditioned for the long winter storage.

Written by Chris Gorsuch 11/2000

 Published in PA Angler & Boater magazine Sept/Oct 2001