Top 10 pre-season
jet ski checks

2. Inspect the fuel system

Old fuel can degrade over time, leading to clogged injectors and poor engine performance. To make sure your engine runs smoothly:

• Drain any leftover fuel from the tank
• Inspect the fuel lines for cracks, wear, or leaks.
• Replace the fuel filter, especially if it’s dirty or clogged.
• Refill the tank with fresh fuel and consider using a quality marine-grade fuel stabiliser.

3. Engine and cooling system checks

Your jet ski’s engine and cooling system are crucial for reliable performance. Before starting the season:

• Check the oil level and change it if necessary (4-stroke models).
• Inspect the coolant levels (if your jet ski has a closed-loop cooling system).
• Flush the cooling system with fresh water to remove any salt, debris, or residue from last season.
• Look over the spark plugs—clean or replace them if worn.

4. Inspect the hull and jet pump

A damaged hull or clogged jet pump can seriously affect performance. Before launching:

• Inspect the hull for cracks, chips, or signs of damage.
• Clean the intake grate and impeller, removing any debris or marine growth.
• Ensure the pump and impeller spin freely and aren’t damaged.

5. Test the steering and throttle

A jet ski’s maneuverability depends on responsive steering and throttle control.  Check the following before leaving shore:

• Move the handlebars from side to side to ensure they turn smoothly.
• Test the throttle lever for smooth operation. responsiveness, and any signs of sticking or lagging. The lever should return to its original position quickly when released.
• If anything feels stiff or unresponsive, lubricate the necessary components or seek professional help.

6. Check safety gear and accessories

Safety is just as important as performance. Ensure you have the proper safety equipment and that everything is in working order:

• Carry out an annual service on your life jacket or buoyancy aid.
• Check that your lanyard kill switch is in good condition and functioning properly. To test it, start your jet ski and pull the lanyard—your engine should immediately shut off.
• If your jet ski has a GPS, radio, or navigation lights, check that they are functioning correctly.

7. Check your insurance is up to date

In the event of an accident, don’t be caught short with a big bill to pay. Before launching:

• Make sure your jet ski’s insurance policy provides the necessary coverage.
• If you haven’t got insurance, get a quote with us today: Jet Ski Insurance | HavenKJ Specialist.

8. Inspect the trailer and towing equipment

Don’t forget the trailer!  Here in the UK it is a legal requirement to maintain a trailer in a roadworthy condition.

• Check tyre condition & tread, and ensure they are properly inflated.
• Ensure lights, brakes, and hitch connections are secure.
• Lubricate moving parts such as the winch and wheel bearings.

9. Skill up!

If you aren’t an experienced jet ski user, think about going on a course. The RYA run a number of courses which you may find useful such as their Personal Watercraft Proficiency course. You can visit their website to find a course near you:  RYA Personal Watercraft courses

Many UK harbours require Jet ski riders to hold an RYA qualification in order to launch their jet ski.