Quick Overview:
- Genuine Yamaha four-stroke service kits retail from about $106 for a 2.5hp to $586 for a V8.
- Labour adds roughly $300 to $600 for an annual service on a single outboard.
- New motors need an early first service, at 20 hours for Yamaha and 3 months or 20 hours for Mercury.
- After that, plan on a service every 100 hours or 12 months, whichever comes first.
- The real cost risk is what the service finds, so a skipped service rarely saves money.
By Victory Parts, Last updated October 2026. Prices are a guide only, and will vary with your motor, location and mechanic.
An outboard motor service in Australia costs the parts plus the labour, and both scale with the motor. On a small portable, the parts for a full annual service can come in under $110. On a V6 four-stroke, the genuine parts kit alone can top $500, before anyone picks up a spanner. Add workshop labour of roughly $300 to $600 for an annual service and most owners are looking at roughly $400 to $1,200 a year per motor, before any extra work.
This guide breaks the bill down: what a standard service includes, what the parts cost by engine size using real Australian prices, where the labour goes, and what you can do yourself. We sell the parts, so we’ve kept the numbers to published prices you can check.
What’s in a Standard Outboard Motor Service
Every brand publishes its own schedule, but the bones are the same. Yamaha’s maintenance chart sets three service points for a four-stroke: after the first 20 hours on a new outboard, every 50 hours for some checks, and the main service annually or every 100 hours. The items on Yamaha’s replacement list are the ones you’ll see on most invoices:
- Engine oil and oil filter
- Gearcase lube
- Spark plugs
- The 10-micron fuel/water separating filter and the on-engine fuel filters
- Water pump impeller
- Power trim and tilt fluid
Yamaha’s 100-hour kits for the F115 to F300 also include anodes. Mercury’s timing is close: Mercury-certified service centres describe an extra service on new engines at 3 months or 20 hours, whichever comes first, then every 12 months or 100 hours.
The 12-month rule catches a lot of weekend boats. A motor that does 40 hours a year still needs its annual service, because the calendar limit comes first.
Outboard Motor Service Cost: Parts by Brand and Engine Size
Service kits are brand and model specific. The oil filter, impeller, spark plugs and gaskets in a Yamaha kit won’t fit a Mercury, and even within one brand the kit changes with engine size and model year. So the parts bill depends on what you run, and on what’s in the kit.
Same size motor, very different kits
Here’s what a genuine kit for a mid-size four-stroke costs at Australian retail in October 2026, and what you get for the money:
- Yamaha 75 to 90hp: $332.42 to $362.32 depending on model year. Includes 5 litres of engine oil, a litre of gear oil, the oil filter, drain plug gaskets, the impeller with its gasket and spacer, and four spark plugs. No fuel filter or anodes.
- Mercury 75 to 115hp (100-hour kit): about $53. An oil filter, an inline fuel filter and two gear case seals. Oil, plugs and the water pump kit are bought separately.
- Suzuki DF140 (2010 to 2012): $265.95. Oil filter, fuel filter, water pump repair kit, four spark plugs, four anodes, gaskets and O-rings. No engine or gear oil.
- Honda BF90 (carburetted BF90AT): $512 with genuine Honda oils, or $398 without. Four spark plugs, water pump impeller kit, oil and fuel filters, 5 litres of engine oil, a litre of gear oil with pump, a thermostat gasket and drain washers.
- Tohatsu MFS75 to MFS140: $359.95. Oil filter, water pump impeller with guide plate and pump liner, four spark plugs, 15 anodes, gaskets and O-rings. No oil or fuel filter.
Five brands, five different boxes. On price alone the Mercury kit looks like a fraction of the others, but add oil, plugs and a water pump kit and the gap closes fast. The Tohatsu kit carries a full set of anodes, while the Yamaha and Honda kits are the only ones with oil in the box. Compare kits by what’s inside, not the number on the tag.
Aftermarket kits are also sold in Australia for Honda, Suzuki, Mercury, Tohatsu and older Johnson and Evinrude motors, generally from around $100 to $310 depending on the motor. Check the contents list the same way.
How parts cost climbs with horsepower
Yamaha publishes a genuine four-stroke kit for every size, which makes it a useful guide to how the parts bill grows with the motor. Other brands follow the same pattern, but their kits contain different things, so treat these as a Yamaha guide rather than a price for every brand. Australian retail, October 2026:
- 2.5hp: about $106 to $127
- 4 to 6hp: about $109 to $129
- 8 to 25hp: about $134 to $204
- 30 to 60hp: about $222 to $264
- 70 to 100hp: about $292 to $362
- 115 to 130hp: about $342 to $367
- 150 to 200hp four-cylinder: about $367 to $396
- 200 to 300hp V6: about $389 to $516
- 300 to 350hp V8: about $586
Oil-change-only kits are cheaper, from $77.95 for Yamaha’s 9.9 to 70hp kit to $134.95 for its 200 to 250hp kit, but they’re an oil change, not a service.
Labour: Where the Rest of the Money Goes
Labour is the part of the boat motor service cost that varies most. For a standard annual service on a single outboard, expect to pay roughly $300 to $600 in labour on top of parts. Bigger motors take longer, and the water pump job is the main swing: on most outboards the gearcase has to come off to reach the impeller.
When you ask for a quote, ask the same four questions of every workshop:
- Is it a fixed price or hourly, and how many hours are allowed?
- Does the price include the impeller, fuel filters and anodes, or only oil, filter, plugs and gear oil?
- Are the parts genuine or aftermarket, and which brand?
- Will the service be logged with the manufacturer if the motor is under warranty?
That last one matters on newer motors. Mercury-certified service centres log services with Mercury Marine Australia through its national Merclink system, which is how service history gets attached to a warranty.
Worked Example: Annual Service on a 90hp Four-Stroke
Here’s how the boat motor service cost stacks up on a common motor, a Yamaha F90 at its annual service:
- Genuine Yamaha 75 to 90hp service kit: $332.42 to $362.32, depending on model year
- Fuel/water separator element and any anodes that are due: extra, because the typical kit doesn’t include them
- Labour: roughly $300 to $600
That puts a clean annual service at roughly $630 to $960 before the extras, and anything the mechanic finds comes on top. Do the work yourself and the bill drops to the cost of the parts: a few hundred dollars, plus the gear oil pump if you don’t own one.
What Pushes the Bill Up
The quoted price covers a motor with nothing wrong with it. The final invoice reflects what the mechanic finds once the covers are off. These are the usual add-ons, priced from our own range so you can see the scale:
- Water pump housing as well as the impeller. If the old housing is scored, it gets replaced with the impeller. Our water pump service kits without a housing start at $33.61, while kits that include it, such as the Tohatsu 369-87322-1 at $68.64 or the OMC 395060 at $116.55, cost more.
- Thermostats. If one fails testing, it gets replaced on the spot. A stainless 60 degree thermostat is $40.04 in our range. See our guide on how to check an outboard thermostat.
- Gearcase work. If the gear oil comes out milky, water has got in and the seals need attention before the gearcase is refilled. That’s extra labour plus gear case parts.
- Anodes. They’re due once they’re about half consumed. On a motor with several anodes, that adds up.
None of these are upsells. They’re the reason the service exists. A worn impeller replaced at the annual service is a small line item; one that fails on the water can overheat the powerhead.
Outboard Service Kit or Build Your Own?
A genuine outboard service kit is convenient: one part number, everything for the job. The catch is that you pay for everything in it whether you need it or not, and some kits leave out the fuel filters and anodes.
Building your own list costs a little more time and lets you choose part by part. For high-volume service items like impellers, filters, spark plugs and anodes, quality aftermarket parts from specialist makers are a sound choice, and our guide to genuine vs aftermarket outboard parts goes through where to save and where to spend.
We stock the components across the major brands: water pump service kits, outboard oils, fuel and oil filters, spark plugs, anodes and thermostats. Email online@victoryparts.com.au with your motor’s model and serial number and we’ll put the list together for you, so you get a complete outboard service kit without paying for parts you don’t need.
Doing Your Own Outboard Motor Service
The main saving from DIY is the labour. Oil and filter, gear oil, spark plugs, fuel filters, anodes and the impeller are all owner-level jobs with basic tools and a workshop manual. Powerhead internals, injector work and electronic diagnostics are workshop territory.
If you do your own servicing, keep a logbook with dates, engine hours and the parts used, plus the receipts. It helps when you sell the boat and if you ever need to make a warranty claim. Check your warranty terms before your first DIY service on a newer motor.
Our outboard maintenance tips cover the step-by-step for each job.
Two-Strokes Cost Less to Service
A two-stroke has no engine oil or oil filter to change, so the parts bill is lighter. Genuine Yamaha two-stroke service kits retail from $89.95 for a 2 to 3hp up to $278.80 for a 225 to 250hp. You’re still paying for the gear oil, spark plugs, impeller and labour, and the oil injection system needs checking on motors that have one.
How to Keep Service Costs Down
- Flush after every use, especially in salt or brackish water. Our guide on how to flush an outboard motor covers the method.
- Keep fuel clean. Change the fuel/water separating filter on schedule and use a fuel stabiliser. Water and stale fuel cost far more to fix than a filter costs to change.
- Don’t skip the annual. The 12-month limit is there because oil and rubber parts age whether the motor runs or not.
- Buy parts before the job. If a workshop is doing the labour, ask whether they’ll fit parts you supply. Not all will, so ask first.
Frequently Asked Questions
How much does a 100-hour outboard service cost in Australia?
Parts for a genuine Yamaha four-stroke kit run from about $106 on a 2.5hp to $586 on a V8, with most mid-size motors between $222 and $396. Labour adds roughly $300 to $600, depending on the motor and the workshop.
How often should an outboard motor be serviced?
Every 100 hours or 12 months, whichever comes first, after an early first service on a new motor. Yamaha sets that first service at 20 hours; Mercury-certified centres describe it as 3 months or 20 hours.
Is the 20-hour first service worth paying for?
On a new motor, yes. It’s part of both Yamaha’s and Mercury’s schedules, and on a motor under warranty you want the service on record.
What’s included in an outboard service kit?
It depends on the kit. A typical genuine four-stroke kit includes engine oil, gear oil, the oil filter, drain plug gaskets, spark plugs and a water pump impeller with its gasket. Some leave out fuel filters and anodes, so check the list.
Can I service my own outboard?
Routine servicing is within reach of most owners with basic tools and a manual. Keep a logbook and receipts, and check your warranty terms before you start on a newer motor.
Why is a big outboard so much dearer to service?
More oil, more spark plugs, bigger filters and more labour. A V6 Yamaha kit carries more oil and six spark plugs, which is why it can cost up to about double a 60hp kit.
Pricing up your next service? Email online@victoryparts.com.au with your motor’s model and serial number, or call 07 5211 1675, and we’ll match every part on the list. Workshops can apply for a trade account.
About the author
Victory Parts
Victory Parts supplies outboard parts to boaties, marine workshops and mechanics across Australia from its warehouse at Kunda Park on the Sunshine Coast, with service parts for Yamaha, Mercury, Suzuki, Honda, Tohatsu, Johnson and Evinrude motors.
This information is general in nature and doesn’t take your specific boat, motor or conditions into account. Always check your owner’s manual or the manufacturer’s specifications before fitting parts or doing maintenance, and talk to a qualified marine mechanic if you’re unsure. Not sure what fits? Email online@victoryparts.com.au with your engine model and we’ll help you find the right part.
