Technical Tidbits: Winterizing Your Outboard

Bill Grannis, Evinrude technician and historian


Now that Fall is here and the warm weekends have disappeared, it’s time to think about that inevitable seasonal chore called winterizing. You may not experience freezing temperatures where you live, but your boat and motor still have to be prepared for long-term storage. Your dealer, the owners manual, boating internet forums, and other sources of information will all tell you: Proper protection procedures prevent premature problems.


Rust, corrosion, and the decomposition of fuel work their evil during periods of non-use. Be sure to follow your owners manual and the service literature concerning winterizing your specific outboard model. The following is a general description of recommended winterizing practices.



The best time to add fuel stabilizers is at the last boating trip of the season. That way the whole system gets thoroughly treated. If that’s not possible, add the stabilizer to the tank at least the day before you winterize the boat to let it mix thoroughly with the remaining gasoline. Be sure to fill the tank to eliminate the chances of condensation forming and dripping to the bottom during temperature changes. Follow the additive mixing directions carefully; the right amount is good, but more is not always better.


Drain and refill the gear oil and inspect for chunks of metal on the drain screw magnets, as shown below. Use new gaskets under the screws. For Evinrude E-TEC engines with extended service intervals compared to older motors, it would be a good idea to make sure there is no water that mixed with the oil, which could be a problem.



Remove the prop, then check for fishing line in the seal, damaged propeller blades, and eaten-away “zinc” anodes. Grease the shaft, but leave the prop removed for safety while running the motor. Lubricate all the grease fittings and required moving parts according to the manual. Put a film of grease on the trim rams and on the tilt ram, if equipped.


Perform a visual check of the engine looking for any worn, broken or missing parts, corroded items, and for wiring or fuel system abnormalities. Hook up water to the engine and let it run for at least ten minutes to flush out the engine and to allow the stabilized gasoline to reach the powerhead. Evinrude E-TEC outboards have special winterizing instructions listed in their owners manuals and they should be followed explicitly.

Fogging Oil (#777186) can be purchased with an injection hose (#763644)

to simplify winterizing procedures on carbureted motors equipped with a maintenance valve on the engine primer. Other motors require the air silencer to be removed and the fogging oil sprayed through each intake until the engine smokes profusely. Remove the spark plugs and spray fogging oil into each cylinder. Turn the motor over a few revolutions to distribute the oil along the cylinder walls.


As the motor drains and cools, check out the boat systems, steering system, and electrical systems for problems or wear. Clean and lube the steering rams on rigs with mechanical steering. Hydraulic systems should be topped off and marine grease applied to the cylinder ram to prevent corrosion and pitting. Boats used in saltwater environments should be cleaned with boat soap and warm water to get rid of salt residue.

If equipped with the speedometer pickup located in the front of the gearcase, make sure the hose is removed and the gearcase hole and fitting cleaned out to prevent any freeze damage from trapped water.


Store the boat with the bow elevated to drain any water that might get inside. The motor should be in the vertical position to keep the through-hub exhaust from holding water and to retract the trim-tilt rams.



Touch up any scratches or nicks on the motor with the manufacturer’s spray paint. Apply a coat of marine wax to the boat and motor. Coat the powerhead with a silicone spray (#775630) to stop any corrosion from forming and to lubricate moving parts. Keep the silicone away from the starter “bendix” to prevent slippage. Remove the battery and charge it fully. Store the battery in a cool, dry place.


Service the trailer, if needed. Re-pack the wheel bearings, repair any corroded areas, check the lighting, and, if equipped, inspect the brake system along with the wheels and tires.


By following these procedures along with the items in your owners manual, you will extend the life of your motor and prevent problems that could spoil your first outing next spring.


* * * * * *

Have more questions about winterizing or boat maintenance? Need clarification on any of these instructions? Head over to the E-NATION message boards, where other Evinrude owners (including Bill Grannis, the author of this article) are there to help.