Jet skis offer high-speed thrills and fun on the water but can quickly become a mechanical nightmare without proper maintenance. Many owners assume that jet ski maintenance requires minimal upkeep, but neglecting routine maintenance can lead to expensive repairs, poor performance, and even complete breakdowns.
From engine damage and electrical failures to impeller issues and corrosion, small problems can snowball into major repair bills if left unchecked. In this guide, we’ll break down the 10 costly problems that can happen when you neglect jet ski maintenance and how to prevent them.
1. Engine Damage from Old Oil and Overheating
One of the biggest consequences of skipping jet ski maintenance is engine failure, often caused by old, dirty oil and overheating. Like a car, a jet ski engine needs fresh oil to lubricate moving parts and prevent excessive wear. Over time, oil breaks down, loses its protective properties, and can lead to increased friction and overheating.
If you don’t flush the cooling system after each ride, salt, sand, and debris can clog the cooling passages, making it difficult for the engine to regulate its temperature. This can lead to warped cylinders, blown head gaskets, or even total engine failure, resulting in costly repairs that could have been avoided. Overheating can also cause seals and gaskets to degrade, leading to oil leaks and further engine damage.
How to Prevent It:
- Change the oil every 50 hours of use or at least once per season.
- Flush the engine with fresh water after every ride, especially in saltwater conditions.
- Monitor the temperature gauge to ensure your engine isn’t overheating.
2. Battery Failure from Lack of Charging or Corrosion
Many jet ski owners are caught off guard when their PWC won’t start after sitting for a few weeks or months. The most common reason? A neglected battery. Unlike cars, jet skis don’t recharge their batteries as efficiently during use, meaning they need regular charging.
If left sitting for too long, a jet ski battery can lose charge, corrode, or completely die, leaving you stranded when you’re ready to ride. Batteries exposed to moisture and saltwater degrade even faster, shortening their lifespan. A neglected battery can also cause electrical malfunctions, affecting ignition, lights, and dashboard displays.
How to Prevent It:
- Charge the battery at least once a month during the off-season.
- Store it in a cool, dry place and disconnect it if the jet ski won’t be used for a while.
- Use a trickle charger or battery tender to maintain charge levels.
3. Fuel System Problems from Stale Gas and Clogged Injectors
Leaving old fuel in your jet ski for too long can cause serious fuel system issues, especially if it contains ethanol. Ethanol absorbs moisture over time, leading to fuel separation, water contamination, and clogged fuel injectors. This can make your jet ski hard to start, cause sputtering, and reduce performance. If the fuel system becomes too clogged, the engine may fail to start completely, requiring an expensive repair or cleaning service. Stale fuel can also cause carburetor issues, making it harder for the engine to receive the proper air-fuel mixture.
How to Prevent It:
- Always use fresh, high-quality fuel, and avoid letting fuel sit for more than a few months.
- Add a fuel stabilizer before storing your jet ski to prevent fuel degradation.
- Run the engine for a few minutes after adding a stabilizer to circulate it through the system.
4. Cooling System Blockages from Salt and Debris
Jet skis use an open-loop cooling system, which pulls in water to regulate engine temperature. However, salt, sand, and debris can accumulate inside the system, leading to overheating and corrosion. If the cooling passages become clogged, the engine won’t cool properly, causing it to run hotter and increasing the risk of severe engine damage. Over time, mineral buildup can restrict water flow, putting excessive strain on your cooling system and reducing overall efficiency.
How to Prevent It:
- Flush the cooling system with fresh water after every ride to remove salt and debris.
- Avoid riding in shallow water with excessive sand or weeds.
- If your jet ski runs hotter than usual, have a professional inspect the cooling system.
5. Impeller Damage That Reduces Speed and Acceleration
The impeller propels your jet ski forward, and any damage to it will reduce speed, acceleration, and fuel efficiency. Many owners unknowingly damage their impellers by riding in shallow water, where sand, rocks, and debris get sucked into the intake. A bent, chipped, or clogged impeller can cause vibrations, power loss, and rough handling, making your jet ski feel sluggish or unresponsive. Long-term impeller issues can also strain the jet pump, leading to additional mechanical problems.
How to Prevent It:
- Avoid riding in water less than three feet deep.
- Regularly monitor the intake grate and impeller for debris or damage.
- Have a professional inspect the impeller if you notice vibrations or performance issues.
6. Corrosion and Rust That Weaken Key Components
Saltwater is highly corrosive, and if you don’t rinse your jet ski thoroughly after each ride, rust can form on metal parts, electrical connections, and engine components. Corrosion can lead to weakened structural integrity, electrical failures, and mechanical breakdowns. Over time, rust can eat away at essential parts, leading to expensive replacements and safety risks. Corroded components can also make routine maintenance more difficult, as bolts and screws may seize up.
How to Prevent It:
- Rinse your jet ski with fresh water after every ride, paying extra attention to metal components.
- Apply marine-grade anti-corrosion spray to bolts, engine parts, and electrical connections.
- Store your jet ski in a dry, covered area to prevent excess moisture buildup.
7. Electrical Failures from Water Exposure
Water and electrical systems don’t mix, and if wiring, sensors, or connectors are exposed to moisture, it can cause ignition problems, dashboard malfunctions, and even engine failure. Over time, electrical connections can loosen, corrode, or short-circuit, leading to random power losses or complete shutdowns while riding. A faulty electrical system can also affect the bilge pump, lights, and engine sensors, making diagnostics and repairs more complicated.
How to Prevent It:
- Inspect wiring and electrical components regularly for signs of corrosion.
- Use dielectric grease on connectors to keep out moisture.
- Store your jet ski in a dry, covered location to prevent excessive exposure to rain and humidity.
8. Worn-Out Steering System That Affects Handling
Neglecting jet ski maintenance can cause steering cables and linkages to deteriorate, making your jet ski harder to maneuver. If your jet ski’s steering feels loose, stiff, or unresponsive, it could be due to rusted or frayed cables. If left unchecked, complete steering failure can occur, posing a serious safety risk. Faulty steering can also cause uneven turns, making the ride feel unstable.
How to Prevent It:
- Check the steering system at least once a season for wear or corrosion.
- Lubricate the steering cables and replace them if they show signs of fraying.
9. Damaged Hull That Leads to Leaks
The hull is your jet ski’s first line of defense, and cracks, dents, or deep scratches can allow water to seep inside. Small leaks can lead to internal corrosion and electrical damage, making it crucial to inspect the hull regularly. A compromised hull can also affect buoyancy, making your jet ski feel unstable or harder to maneuver. If water seeps into areas like the engine bay or fuel system, it can cause severe mechanical damage, leading to expensive repairs.
How to Prevent It:
- Inspect the hull for cracks, scratches, or impact damage after every ride.
- Use a marine-grade sealant to patch minor issues before they worsen.
- Avoid riding in rocky or debris-filled areas that could cause damage.
10. Expensive Repairs and Premature Jet Ski Failure
The worst-case scenario? Your neglected jet ski breaks down completely, leading to repairs that could cost thousands of dollars—or even require a full engine replacement. When minor issues like dirty oil, clogged cooling systems, or corroded parts are ignored, they often lead to major mechanical failures. Eventually, the cost of repairs may exceed the value of the jet ski itself, forcing you to consider replacing it entirely.
How to Prevent It:
- Stick to a regular maintenance schedule, including oil changes, battery checks, and flushing the engine.
- Hire a professional jet ski maintenance service for seasonal inspections.
- Address small issues as soon as they arise to prevent expensive repairs later.
