Seasonal Maintenance: How to Winterize a Jet Ski
At Habberstad Powersports, we understand that proper winterization protects your jet ski investment and ensures reliable performance when spring arrives. Long Island's harsh winter conditions can cause significant damage to personal watercraft if proper preparation steps are skipped or performed incorrectly. Our service technicians have winterized thousands of jet skis over the years, and we're sharing our professional knowledge to help you protect your investment.
Understanding Why Winterization Matters
Water remaining in your jet ski's cooling system expands when frozen, potentially cracking the engine block, exhaust manifold, or cooling passages. These repairs can cost thousands of dollars and often aren't covered under warranty since they result from improper storage preparation. Even in milder climates, water left in the system can cause corrosion and mineral buildup that reduces performance and shortens engine life.
Fuel degradation presents another significant concern during extended storage periods. Modern ethanol-blended gasoline can separate and form harmful deposits that clog fuel injectors and damage internal engine components. Untreated fuel can also absorb moisture from the air, leading to corrosion in the fuel tank and delivery system.
Battery deterioration accelerates during cold weather storage. Lead-acid batteries lose capacity as temperatures drop, and a completely discharged battery can freeze and crack. Proper battery maintenance during storage prevents these issues and ensures reliable starting when you're ready to return to the water.
Essential Tools and Supplies
Before beginning the winterization process, gather all necessary tools and supplies to avoid interruptions. You'll need a standard socket set, screwdrivers, pliers, and a funnel for fluid changes. A wet/dry vacuum proves invaluable for removing water from hard-to-reach areas.
Marine-grade antifreeze represents the most critical supply for winterization. Never use automotive antifreeze, which contains toxic ethylene glycol that harms marine environments. Propylene glycol-based marine antifreeze provides adequate freeze protection while remaining environmentally safe. Purchase at least two gallons for most jet ski models.
Fuel stabilizer prevents gasoline degradation during storage. Choose a marine-specific stabilizer designed for ethanol-blended fuels. These products typically treat 25-50 gallons of fuel per bottle, making them cost-effective for multiple seasons. Quality fuel stabilizers also include corrosion inhibitors that protect metal components in the fuel system.
Fogging oil lubricates internal engine components during storage, preventing corrosion and ensuring proper lubrication at startup. Marine fogging oil is specifically formulated for two-stroke and four-stroke marine engines. The aerosol cans simplify application through the intake system.
A battery tender or trickle charger maintains proper battery charge throughout the storage period. These devices automatically adjust charging rates based on battery condition, preventing overcharging while maintaining optimal charge levels. Quality units include temperature compensation for varying storage conditions.
Step-by-Step Winterization Process
Begin winterization by running the jet ski on a trailer or lift to warm the engine to normal operating temperature. This ensures complete oil circulation and makes oil changes more effective. Never attempt winterization with a cold engine, as thick oil won't drain completely and may hide developing problems.
Remove the drain plugs from the hull to eliminate any water that may have entered during use. Even small amounts of water can freeze and cause gelcoat damage or structural problems. Inspect the drain plugs for damage and replace if necessary. Apply marine-grade sealant to threads when reinstalling.
Change the engine oil while the engine remains warm. Used oil contains contaminants and acids that can cause corrosion during storage. Drain the old oil completely, replace the oil filter, and refill with fresh marine engine oil. Check your owner's manual for the correct oil type and capacity specifications.
Fill the fuel tank completely and add the appropriate amount of fuel stabilizer. A full tank minimizes air space, reducing condensation formation during temperature fluctuations. Run the engine for at least ten minutes to circulate the treated fuel throughout the system, ensuring complete protection of all fuel system components.
Cooling System Winterization
The cooling system requires the most attention during winterization since freeze damage can destroy expensive engine components. Start by locating all drain plugs and petcocks in the cooling system. Most jet skis have multiple drain points that must be opened to ensure complete water removal.
Connect a flush adapter to the cooling system intake and use a garden hose to flush fresh water through the system. This removes salt, sand, and other contaminants that can cause corrosion during storage. Continue flushing until the water runs clear from all drain points.
After draining all water from the cooling system, close all drain plugs and petcocks securely. Pour marine antifreeze into the flush adapter while running the engine at idle speed. Continue adding antifreeze until it appears at all cooling system outlets, indicating complete circulation through the system.
The exhaust system also requires antifreeze protection since water remains in the exhaust manifold and cooling passages after normal operation. Pour antifreeze directly into the exhaust outlet while tilting the jet ski to ensure complete coverage of all internal passages.
Remove the thermostat housing and inspect the thermostat for proper operation. Replace the thermostat if it shows signs of corrosion or fails to open at the correct temperature. Clean the thermostat housing thoroughly before reassembly with fresh gaskets or O-rings.
Engine Internal Protection
Fogging the engine protects internal components from corrosion during storage. Remove the air intake cover and start the engine while gradually spraying fogging oil into the intake system. The engine will begin smoking heavily as the fogging oil burns, which is normal and expected.
Continue spraying fogging oil until the engine stalls from the rich mixture. This ensures complete coating of pistons, cylinder walls, and valves with protective lubricant. Allow the engine to sit for several minutes before attempting to restart, giving the fogging oil time to coat all surfaces thoroughly.
Remove the spark plugs and inspect them for wear or fouling. Clean or replace plugs as needed, gapping them to manufacturer specifications. Pour a small amount of fogging oil into each cylinder through the spark plug holes, then reinstall the plugs finger-tight to prevent moisture entry.
Spray fogging oil into the carburetor or throttle body opening while manually operating the throttle mechanism. This protects the fuel delivery components and ensures proper lubrication of throttle shafts and butterfly valves. Cover the intake opening with a plastic bag secured by a rubber band to prevent moisture entry.
Fuel System Preparation
Drain the fuel tank if you prefer not to store the jet ski with fuel. However, an empty tank can collect condensation and develop rust or corrosion issues. If draining the tank, add a small amount of fogging oil and slosh it around to coat the interior surfaces before storage.
Disconnect the fuel lines and drain them completely if possible. Water trapped in fuel lines can freeze and crack these components. Blow compressed air through the lines to remove residual fuel and moisture, then reconnect all fittings securely.
Clean or replace the fuel filter to ensure unrestricted fuel flow when spring arrives. Contaminated filters can cause poor performance and potential engine damage. Use only marine-grade fuel filters designed for your specific jet ski model.
Inspect all fuel system components for leaks, cracks, or deterioration. Replace any questionable components before storage to prevent problems during the next season. Pay particular attention to fuel lines, which can develop cracks from ozone exposure and temperature cycling.
Electrical System Maintenance
Remove the battery from the jet ski for indoor storage in a temperature-controlled environment. Clean the battery terminals with baking soda and water to remove corrosion, then apply terminal protectant to prevent future corrosion. Charge the battery fully before storage.
Connect a battery tender to maintain proper charge levels throughout the storage period. These devices prevent sulfation, which permanently damages battery plates and reduces capacity. Check the battery monthly and add distilled water if needed for serviceable batteries.
Inspect all electrical connections for corrosion or damage. Marine environments are particularly harsh on electrical components, and small problems can become major issues if left unaddressed. Apply dielectric grease to connections to prevent corrosion during storage.
Test all electrical systems before storage to identify any developing problems. Check the starter, ignition system, gauges, and accessories for proper operation. Address any issues before storage rather than discovering them when you're eager to get back on the water.
Hull and Exterior Care
Wash the hull thoroughly with marine soap to remove salt, algae, and other contaminants. Pay special attention to the jet pump area, where sand and debris commonly accumulate. Use a soft brush to clean textured surfaces without damaging the gelcoat finish.
Apply a quality marine wax to protect the gelcoat during storage. Wax creates a barrier against UV rays and environmental contaminants that can cause fading and oxidation. Buff the wax to a high gloss for maximum protection and improved appearance.
Inspect the hull for damage such as scratches, chips, or stress cracks. Small gel coat repairs are much easier and less expensive when addressed promptly. Clean any damaged areas thoroughly and apply appropriate repair materials according to manufacturer instructions.
Remove all cushions, covers, and fabric items for indoor storage. These materials can retain moisture and develop mold or mildew if left in the jet ski during storage. Clean all items thoroughly before storage and allow them to dry completely.
Storage Environment Considerations
Choose a storage location that provides protection from the elements while allowing adequate ventilation. Enclosed storage prevents UV damage and reduces temperature extremes, but trapped moisture can cause problems if ventilation is inadequate. Ensure air circulation around the stored jet ski.
Cover the jet ski with a breathable cover designed for marine applications. Avoid plastic tarps, which can trap moisture and promote corrosion. Quality covers allow moisture vapor to escape while protecting against dust and debris accumulation.
Block the jet ski securely on the trailer or storage stand to prevent movement during storage. Check tire pressure on the trailer and add blocks under the axles to prevent flat spots. Lubricate all trailer bearings and inspect the coupler and safety chains.
Position the jet ski slightly nose-down to encourage any remaining water to drain toward the bilge area. This prevents water from pooling in other areas where it might freeze and cause damage. Place absorbent pads in the bilge to collect any residual moisture.
Spring Preparation Checklist
When spring arrives, reverse the winterization process systematically. Start by inspecting all systems for damage that may have occurred during storage. Look for signs of rodent activity, which is common in stored watercraft.
Remove the antifreeze from the cooling system by flushing with fresh water until no antifreeze remains. Antifreeze can cause overheating if left in the system during operation. Check all drain plugs and ensure they're properly installed and tightened.
Change the engine oil even if it was changed during winterization. Oil can absorb moisture during storage, and fresh oil ensures optimal lubrication for the new season. Replace the oil filter and check all fluid levels before first startup.
Reinstall the battery after verifying full charge and proper electrolyte levels. Check all electrical connections and test systems for proper operation. Clean any corrosion that may have developed during storage and apply fresh dielectric grease.
Professional Service Benefits
While many jet ski owners can perform basic winterization, professional service ensures nothing is overlooked. Our certified technicians have extensive experience with all jet ski brands and models, understanding the specific requirements for each application.
Professional winterization includes comprehensive inspections that can identify potential problems before they become expensive repairs. Our technicians check wear items, adjust components, and perform preventive maintenance that extends your jet ski's service life.
We maintain detailed service records for each customer, tracking maintenance history and identifying patterns that might indicate developing issues. This proactive approach prevents unexpected breakdowns and ensures reliable operation throughout the boating season.
Our facility provides secure indoor storage with climate control and security monitoring. Professional storage eliminates concerns about theft, weather damage, and improper storage conditions that can affect your jet ski's condition and performance.
Contact Habberstad Powersports
Our service department remains ready to assist with all your winterization needs. Whether you prefer professional service or need supplies for do-it-yourself winterization, our knowledgeable staff provides expert guidance and quality products.
Schedule your winterization service early to avoid the rush as temperatures drop. Our technicians work efficiently to minimize your jet ski's downtime while ensuring thorough protection throughout the storage period.
Visit our parts department for all winterization supplies including marine antifreeze, fuel stabilizer, fogging oil, and battery tenders. We stock only quality products proven effective in Long Island's challenging climate conditions.
Contact us today to discuss your winterization needs and schedule service. Proper preparation now ensures many years of reliable jet ski enjoyment and protects your investment in marine recreation.