Short answer: a mobile impeller and water pump job typically runs $240–$500 per engine, done at your dock, marina, or driveway. Where you land depends on your engine and whether the housing is clean enough for a kit or needs a full pump assembly. The standard interval is every 300 hours or 3 years.
How much does outboard impeller replacement cost?
Our typical range for a mobile impeller and water pump job is $240–$500 per engine, done at your dock, marina, or driveway. Where you land in that range depends on your engine and what we find when the lower unit comes off. Multi-engine boats are quoted per setup.
That's the whole answer for most boats. Here's what moves the number.
What makes the price go up or down?
- Impeller kit vs. full pump rebuild. If the housing and wear plate are clean, a kit (impeller, gaskets, O-rings) does it. If the housing liner is scored or melted from a past overheat, the whole pump assembly gets replaced — more parts, same labor visit.
- Engine make and model. Parts pricing varies between Yamaha, Mercury, and Suzuki, and between a 40hp and a 300. Bigger engines mean heavier lower units and sometimes more involved removal.
- Single vs. twins or triples. Each engine is its own pump, its own kit, its own lower unit drop. Multi-engine boats get a per-setup quote.
- Access and condition. Seized lower unit bolts, corroded driveshaft splines, or a lower unit that hasn't been off in a decade add time. Boats serviced regularly come apart easier — one more way maintenance pays for itself.
Why is an impeller the cheapest insurance on your boat?
The impeller is a rubber wheel that pushes every drop of cooling water through your engine. When its vanes crack, take a set, or shred, the engine overheats. Best case, the alarm saves you. Worst case, you cook a powerhead — and a replacement powerhead on a modern four-stroke runs well north of $5,000, often closer to the value of the whole engine.
So the math is simple: a few hundred dollars every few years, or a five-figure risk every trip. Rubber wears out. Don't wait for the alarm.
When should the impeller be replaced?
The standard interval is every 300 hours or 3 years, whichever comes first — and here in Florida, earlier is smarter. Sand in the Indian River Lagoon and our inlets acts like grit in the pump, and salt plus heat ages rubber fast. An impeller that sits unused degrades too; the vanes take a permanent bend from resting in one position. Low hours does not mean healthy impeller.
If your tell-tale stream is weakening or your temp creeps up at idle, don't wait for the interval. Those are the early signs.
What should a proper water pump kit include?
A real water pump service is more than the rubber wheel. A complete job includes:
- New impeller
- Housing or housing liner (cup)
- Wear plate where applicable
- All gaskets and O-rings
- New drive key or pin
If a quote seems cheap, ask what's in the kit. Reusing a scored liner with a new impeller wears the new impeller out early — you paid for a job that's already half-failed. We also check the gear lube for water intrusion while the lower unit is off, because that's the moment it's free to look.
Mobile service or the boatyard?
A yard job means trailering the boat (or paying for haul-out), leaving it in a queue, and driving back for pickup — the impeller swap is often the cheapest line on that invoice. Mobile service means we come to the boat, the lower unit comes off dockside, and you're running the same day. For a job this contained, there's no reason the boat should travel.
We work on Yamaha, Mercury, and Suzuki and cover the Treasure Coast from Port St. Lucie. Tell us the make, model, and year and we'll give you a real number, not a range.
Tell-tale looking weak?
Tell us your engine make, model, and year — we'll quote it before we schedule.
Get a quoteFAQ
Why does the price range from $240 to $500?
Parts. A clean housing needs a kit; a scored one needs a full pump assembly, and kit prices differ by brand and engine size. Labor is similar either way — we don't know which job it is until the pump is open, which is why we quote honestly from a range and confirm on site.
Is it cheaper to do it myself?
On parts, yes. But the job means dropping the lower unit, aligning the driveshaft and shift shaft on reinstall, and knowing a scored liner when you see one. Get it slightly wrong and the engine overheats with a brand-new impeller in it. If you're not confident on the reinstall, this is a poor place to learn.
My boat has low hours. Do I really need it at 3 years?
Yes — arguably more so. Rubber ages whether it spins or not, and an impeller that sat takes a set in its vanes. Time and Florida heat kill impellers as reliably as hours do.
Can you just replace the impeller and skip the rest of the kit?
We won't, and you shouldn't want to. Gaskets and O-rings are one-time-use, and a new impeller in a worn housing fails early. The kit is a small fraction of the job — skipping it saves almost nothing and undermines the whole service.
Do you do this as part of regular maintenance?
Yes. Impeller condition is checked during every 100-hour service, and we replace on the 300-hour/3-year interval or earlier if the boat runs sandy water. If something else turns up while the lower unit is off, our outboard repair work is done dockside too.