A jet ski is easy to love and easy to neglect. You ride it hard on a Saturday, back the trailer into the garage, and that's the last thought you give it until the next warm weekend — which is exactly how a fun machine turns into an expensive one.

Personal watercraft ask for a particular kind of care. Most of what they need isn't hard, but it splits into two rhythms: a few minutes after every ride, and a longer session once a season. Skip the after-ride part and salt quietly eats the engine from the inside. Skip the seasonal part and you find out in spring, when it won't start.

This jet ski maintenance guide walks through both — what to do after each outing, what to handle before storage, and where the line falls between a job you can manage and one worth handing to a dealer.

Intervals and figures below reflect guidance from BRP (Sea-Doo), Yamaha, and established PWC service resources. Your owner's manual is the final word for your specific model — engines and flush procedures vary, and a few of these steps can cause damage if done in the wrong order.

Jet Ski Maintenance Starts With the After-Ride Flush

If you ride in salt water, this is the single most important thing you'll ever do for your ski. Salt left sitting in the engine's cooling passages dries into crystals that corrode and clog the system — and those blocked passages lead straight to an overheated engine. A freshwater flush after every saltwater ride rinses it all out before it can settle.

You connect a garden hose to the flush fitting on the machine, and — this is the part that matters — start the engine first, then turn on the water. Let it idle with water running for about 3 to 5 minutes, then shut the water off before you shut the engine down. Doing it in the wrong order can let water back up into the engine, so check your manual for your model's exact steps the first time. One more rule: never run the engine dry on the trailer for more than about 15 seconds without water, or you'll damage the pump seal.

Fresh-water riders don't have the salt problem, but a flush is still worth doing after riding in silty, sandy, or weedy water, which can leave grit in the same passages.

A flush is a habit, not a scheduled task — but it's the habit everything else rests on. Keep your model's flush procedure (engine-first or water-first, and for how long) in the notes field of your jet ski in Mintain, so you're never guessing at the ramp.

After Every Ride: Rinse, Wipe Down, and Check the Bilge

While the hose is out, rinse the whole machine — hull, seat, handlebars, and especially any metal fittings — to wash off salt and grime before they dry. Wipe it down and let it air out with the seat off, so moisture doesn't sit inside.

Then take ten seconds to look in the bilge, the low point inside the hull. A little water is normal; a lot, or any sheen of oil or fuel, tells you something's leaking and worth chasing down before the next ride.

Every Season: Oil, Filter, and Spark Plugs

Today's four-stroke PWC engines use oil like a car does, and it breaks down the same way. Most manufacturers call for an oil and filter change every 50 engine hours or once a year, whichever comes first — Sea-Doo's smaller Spark models stretch to 100 hours, and supercharged engines often want it more often. Because a season rarely piles up 50 hours, the once-a-year change is the one that usually applies, and it matters even if you barely rode: used oil holds moisture and acids that shouldn't sit in the engine over a long winter.

Spark plugs are an inspect-then-replace item. Manuals ask you to check them periodically, and many owners simply replace them every couple of years to be safe — they're inexpensive, and a fouled plug is a common reason a ski runs rough or won't fire. The fuel filter is another annual-ish item on most models.

Add the Engine Oil & Filter Change template (annually / 50 hours), the Spark Plug Replacement template, and the Fuel Filter Replacement template to your ski in Mintain. Store your oil type, filter part number, and plug gap in the notes so a parts run is a five-minute errand instead of a research project.

The Battery

A PWC battery lives a hard life — vibration, heat, and long stretches of sitting idle. Most last 3 to 5 years. A fully charged 12-volt battery reads about 12.6 to 12.8 volts at rest; noticeably below that after a full charge means it's weakening.

The thing that kills PWC batteries early is being left to slowly discharge over the off-season. A battery maintainer (a "trickle" charger, often around $30 to $60) keeps it topped up through the winter and can add years to its life. Keep the terminals clean and the connections snug, since a loose or corroded terminal causes the kind of no-start that's maddening to trace at the ramp.

The Battery Service template runs annually in Mintain. Log your battery's install date in the notes, so when it drifts into that 3-to-5-year window you can plan a replacement instead of getting surprised by a dead ski on a perfect Saturday.

Every Season: Winterizing for Storage

If you live where the water freezes, winterizing isn't optional — trapped water expanding inside the engine can crack it. The core steps, in order:

Stabilize the fuel. Fill the tank, add marine fuel stabilizer, and run the engine briefly so treated fuel reaches the whole system. This keeps the fuel from gumming up over months of sitting.
Run antifreeze through the cooling system. A non-toxic RV/marine antifreeze pushed through the flush port protects any passages that hold water. This is the step that prevents freeze damage, and the one worth getting exactly right for your model.
Fog the engine. Fogging oil sprayed into the cylinders coats the internals so they don't rust while the machine sits.
Change the oil and filter, if you haven't already this season — do it before storage, not after.
Pull the battery and store it somewhere that won't freeze, on the maintainer.
Wash, dry, and cover the ski, ideally out of the weather.

Come spring, most of this reverses: the Spring De-Winterization step reconnects the battery, checks the fuel, and gets it lake-ready. It's the same seasonal rhythm a boat follows — our spring boat commissioning checklist walks through the larger version if you've got one of those in the driveway too.

Add the Winterization and Spring De-Winterization templates to your ski, both annual. Mintain will surface winterizing as the riding season winds down — the deadline that's easiest to blow past because there's no chirp or warning light telling you it's time.

Don't Forget the Trailer

The trailer is part of the machine, and its wheel bearings are the part most likely to leave you on the shoulder. Bearings should be inspected and repacked with grease about once a year, since they sit submerged every time you launch and water works its way past worn seals. A seized bearing can lock a wheel at highway speed.

Before you tow, confirm the trailer's running lights, brake lights, and turn signals all work, and check the tire pressure — trailer tires lose air just sitting, the same way a car's do. We covered why that matters in Tire Pressure Matters More Than You Think.

The Trailer — Wheel Bearings & Lights template keeps this annual check on your radar, right alongside the ski it carries.

When to Call a Pro

Plenty of this is rinse-and-look work, but some of it belongs with a dealer or marine tech:

No water spitting from the pilot outlet while the engine runs, or any sign of overheating — stop and get it checked. That's a cooling-system problem, not something to ride through.
Winterizing, if you're not confident in the antifreeze and fogging steps. Done wrong, they leave the engine unprotected. A dealer will winterize a ski for roughly $150 to $300, and a full seasonal service package runs more.
A supercharged model. Those engines have a supercharger that needs periodic service on its own schedule — ask your dealer what yours calls for.
Impeller, wear ring, or hull damage. If the ski feels down on power or you hit something, have the pump looked at rather than guessing.
Salt-water skis also carry sacrificial zinc anodes that corrode in place of the metal around them; a tech will check and replace them as part of service.

Track It in Mintain

The after-ride flush is a habit you build. The seasonal tasks — oil, battery, winterizing, the trailer — are the ones that slip, because they come around slowly and quietly, from a machine that spends most of the year parked.

That's the gap Mintain fills. Add your jet ski under the Toys category and apply the templates that fit it: Engine Oil & Filter Change, Spark Plug Replacement, Battery Service, Winterization, Spring De-Winterization, and Trailer — Wheel Bearings & Lights. Each rides its own schedule, and Mintain keeps the history, so next season you'll know exactly what was done and when.

Free for up to 4 items, so your ski and its trailer fit at no cost. Pro is $1/month or $10/year if you track more.

Add your jet ski to Mintain at mintain.app →

Rinse it after every ride and set the seasonal tasks on a schedule, and your ski will be waiting to start on the first warm weekend — instead of waiting on a repair bill.

This is part of Mintain's weekly maintenance blog. Every Monday, we publish a new guide to help you stay ahead of home, auto, yard, and equipment maintenance — so nothing catches you off guard.