Cummins marine · Independent specialists · Melbourne
Cummins marine service, brought to your berth.
Single or twin, pleasure or commercial. Serviced to Cummins’ schedule by independent specialists, with a clear rundown of what’s urgent and what can wait.
- Independent Cummins specialists
- Servicing Melbourne boats since 1995
- At your berth across Port Phillip Bay
- Twin Disc dealer & ZF Service Point
Your setup
Which Cummins setup do you have?
Cummins diesels power flybridge cruisers and working boats alike, usually on shafts through a marine gearbox. Pick the one closest to your boat, or see what we look after behind the engine.
Cummins rates its recreational engines for occasional use, so on a pleasure boat time and salt water age the engine as much as hours do. We service the engine and its sea water side together.
- Engine oil and filters
- Fuel filters, water separator and bleed
- Sea water pump impeller
- Zinc anodes
- Heat exchanger and aftercooler checks
- Exhaust elbow and riser inspection
- Belts, hoses and clamps
- Shaft seal and coupling check
Twin installations
Twin Cummins, one visit.
Many Cummins-powered cruisers run a pair, like the Riviera 47 and Maritimo M52 on twin QSM11s. We service both engines and both gearboxes in the same visit, so the pair stays on one schedule.
- Both engines and both gearboxes serviced in one visit, at your berth where possible
- Side-by-side checks, so a difference between engines shows up early
- A separate record for each engine, the history buyers and surveyors ask to see
- Haul-out work planned with your yard
What you get
You’ll know exactly where your engines stand.
Every service ends with a plain-English rundown. Each item is marked done, keep an eye on, or needs attention, so you can see what’s urgent and what can wait. Anything beyond the service is quoted first.
- A separate record for each engine and gearbox
- Kept for your survey, insurance and resale history
- What’s due next, so you can plan around the season
Under factory warranty?
Cummins’ recreational marine warranty for engines delivered from 2018 expects maintenance to its Operation and Maintenance Manual, with proof the work was done, and doesn’t cover failures caused by parts not supplied by Cummins. Warranty repairs themselves go through a Cummins-authorised repair facility. If your engine is still covered, check your warranty terms and tell us when you book, so we can service it to suit. Your rights under the Australian Consumer Law apply in addition to these terms.
Service rundown
Twin QSM11 · Shaft drive · 1,450 hours
- Done
Engine oil and filters
- Done
Fuel filters and water separators
- Done
Sea water pump impellers
Replaced. Starboard impeller had cracked vanes.
- Done
Zinc anodes
Renewed.
- Done
Gearbox oil
Clean, no sign of water.
- Keep an eye on
Aftercoolers
Light salt crust at one seal. Plan a strip and reseal this winter.
- Done
Exhaust elbows
No weeping or rust.
- Needs attention
Port sea water pump seal
Weeping from the drain hole. Quoted to reseal.
Something not right?
Signs your Cummins wants attention.
Many problems give a warning first. If you’ve noticed one of these, it’s worth a look before it turns into a lost weekend, or a lost day’s work.
Temperature climbing at cruise
Fine at idle but hot under load usually points to the sea water side. A worn impeller, a fouled heat exchanger or old impeller vanes lodged downstream are common causes. We check the whole circuit to find the restriction.
Salt crust around the aftercooler
The sea-water-cooled aftercoolers on many marine Cummins corrode around their seals over time. Left long enough, salt water can reach the intake. Worth a strip, clean and reseal before it gets that far.
Black smoke and won’t reach rated rpm
Often a sign the engine isn’t getting enough air, from a fouled aftercooler or a tired turbo, or that it’s working too hard behind the wrong propeller or a fouled hull. We check the air side and the load before replacing parts.
Rust or weeping at the exhaust elbow
Wet exhaust elbows corrode from the inside out. A failed one can let sea water back into the turbo and cylinders, so it’s worth replacing before it gets there.
Cranks but won’t fire
Usually a fuel supply problem rather than anything terminal: blocked filters, air in the fuel, or a failing electric lift pump on engines that have one. We work through the fuel system first.
A warning light or reduced power
Electronic Cummins engines monitor themselves and can cut power to protect the engine. The cause is usually physical, from cooling or fuel to a corroded sensor connection, so it’s worth finding rather than just restarting.
Timing
Book around the boating season.
A little planning means the boat is ready on the first good weekend, not the third.
78%
of maritime incidents reported in Victoria in 2024–25 were vessel breakdowns, most of them engine failure or running out of fuel.
Source: Safe Transport VictoriaAugust to October
Pre-season service
Book before the rush. November to Easter is our busiest period, so a service in late winter or early spring has the boat ready for the first good weekend.
Book a pre-season serviceNovember to Easter
On the water
Peak boating, and our busiest months. If an alarm won’t clear or something doesn’t feel right mid-season, call us.
Easter to July
Bigger jobs
The best time for higher-hour services, aftercooler and gearbox work, and haul-outs, with the least boating missed.
Who you're dealing with
Independent Cummins specialists, looking after Melbourne boats since 1995.
We’re not a Cummins dealer. We’re an independent marine workshop that services and repairs Cummins engines at your berth or in our Spotswood workshop, with genuine or quality aftermarket parts.
- Independent, not a Cummins dealer
- Genuine or quality aftermarket parts
- Authorised Twin Disc dealer and ZF Marine Service Point
- Also authorised for Volvo Penta and Yanmar
Cummins marine engines we service, old and new
Check the model and serial number on the engine data plate when you book. Cummins also rates each engine for its duty, from High Output for pleasure boats to Heavy Duty and Continuous for working boats, and the rating sets how hard it can be run.
Cummins were fitted, as standard or as an option, to boats like the Riviera 47 Open Flybridge, Maritimo M52, Mustang 43 Sports Cruiser and Mustang 4100 Flybridge. Many of these hulls were also built with other engines, so check the engine plate.
Questions
What Cummins owners ask us
How much does a Cummins service cost?
It depends on the engine, whether you have one or two, and what’s due on its schedule. We confirm all of that and give you a clear quote before any work starts.
Are you a Cummins dealer?
No. We’re an independent marine workshop. We service and repair Cummins engines with genuine or quality aftermarket parts, and we’re an authorised Volvo Penta, Yanmar and Twin Disc dealer, and a ZF Marine Service Point.
Do I need to bring the boat to you?
No. We service Cummins engines at the berth or on the hardstand around Port Phillip Bay. Bigger jobs come into our Spotswood workshop or are done during a haul-out.
How often does a Cummins need servicing?
Cummins sets the schedule for each engine in its Operation and Maintenance Manual, and it varies by model and use. On a QSB6.7, for example, Cummins says the oil service interval increases to 500 hours when running on ultra-low-sulphur diesel. We work to your engine’s own schedule and record every visit.
Which Cummins do I have?
The model and serial number are on the engine data plate, for example QSB6.7 or QSM11. Send us both and we’ll know what you have. Older boats may have a mechanical 6BTA5.9 or 6CTA8.3.
I have twin Cummins. Can you do both at once?
Yes. We service both engines and both gearboxes in the same visit and keep a separate record for each, so the pair stays on one schedule.
How do I book?
Use the booking form at the top of this page or call (03) 9399 5888. We aim to reply within 1 business day.
Ready when the weather is.
Tell us about your Cummins and where the boat is, and we’ll take it from there.
Mariner Engineering is an independent marine service and repair provider and is not an authorised dealer of, or affiliated with, Cummins. Cummins and associated model names are trademarks of their respective owners, used here only to describe the engines we service.