Boat impeller replacement cost runs $240–$650 per outboard engine at a shop, according to the BoatCostCalc impeller calculator, which counts a parts kit plus 1.5–2.5 hours of shop labor. Doing it yourself cuts the bill to the price of the part: one owner writing on Marine How To pays $16.00 for the impeller in a Westerbeke.
How This Ranking Works
The list below ranks the factors by how much each one can move your final invoice, from the largest swing to the smallest. The order comes from the BoatCostCalc formula (parts kit plus shop labor rate times labor hours times engine count times a region multiplier), the Marine How To walkthrough, and two owner threads on iBoats. It is a reading of those published sources, not a price test, and none of them is a quote for your boat.
Price Drivers, Ranked
- Access to the pump. BoatCostCalc says the high end of its range rises with lower-unit access. Marine How To makes the same point from the DIY side: the most complicated part of the job is physical access to the pump. Tight access turns minutes of work into labor hours.
- Kit scope. A bare impeller and a full water-pump kit are different parts bills. BoatCostCalc lists full water-pump kits as a reason the high end climbs, and an iBoats reply put the list price of one outboard kit at $65, with the same kit findable for around $50.
- Corrosion. Seized fasteners and corroded parts add labor on top of the kit, and BoatCostCalc names corrosion as a high-end driver.
- Engine count. The formula multiplies by the number of engines, so a twin-outboard boat is quoted per engine, not per boat.
- Region. The calculator applies a region multiplier because one national marina price does not exist.
- Who does the work. Parts-only pricing is the floor. Anything beyond it is labor, and that is where quotes differ most.
Cost Breakdown at a Glance
| Cost item | Figure | Source |
|---|---|---|
| Outboard shop job, parts plus labor | $240–$650 per engine | BoatCostCalc |
| Shop labor assumed | 1.5–2.5 hours for many outboards | BoatCostCalc |
| Water pump kit, list price for one outboard | $65 (around $50 elsewhere) | iBoats forum reply |
| Impeller for a Westerbeke, bought at a chandlery | $16.00 | Marine How To |
| Same impeller through the engine maker | Almost $38.00 | Marine How To |
| Replacement wear plate | $13.00 | Marine How To |
| DIY time on many engines | Less than 20 minutes | Marine How To |
Do It Yourself or Pay a Pro
Marine How To calls an impeller change a task every boater should consider adding to their DIY maintenance, and says it usually takes less than 20 minutes on many engines. The author found the identical part, down to the embossed Johnson part number, for $16.00 at Hamilton Marine versus almost $38.00 through Westerbeke. That gap is a reason to compare part sources before you buy.
Paying a pro makes sense when access is tight, the lower unit has to come off, or you would rather not risk a missed blade fragment. A failed impeller can throw a blade or lose a chunk that lodges in a hose, elbow or the heat exchanger, and Marine How To warns that finding the missing pieces is a much larger job. If the engine has already overheated, read what drives boat engine repair cost before you assume the impeller is the whole bill.
Outboard, Inboard, and Sterndrive Differences
The $240–$650 range is built for outboards. BoatCostCalc does not publish an equivalent range for inboard or sterndrive engines, so treat any number you see for those as a starting point and ask for a written scope. Inboard and sterndrive raw water pumps sit in different places than an outboard lower unit, which changes access and labor. Our guide to boat engine repair cost ranges by engine type covers how engine layout shifts pricing.
What to Ask Before You Accept a Quote
BoatCostCalc says its figure is a planning range, not an exact provider quote, and tells owners to confirm taxes, yard fees, environmental fees and provider-specific exclusions. Use that as your checklist when you request free, no-obligation estimates from the vetted marine pros you choose on Boatwork:
- Is the quote per engine, and does it include the impeller only or a full water-pump kit?
- What is the engine type: outboard, inboard or sterndrive?
- Is the work done at the shop, or as mobile service at the dock or slip?
- Which yard, environmental or tax fees are added?
- What happens if corrosion or a damaged housing turns up once the pump is open?
If you plan to lay the boat up, an impeller check fits naturally into the boat winterization checklist for engine, water systems and storage.
Frequently Asked Questions
How much does it cost to replace a boat impeller?
BoatCostCalc puts a shop replacement on an outboard at $240–$650 per engine, parts and labor. A do-it-yourself job costs the part, which one Marine How To author paid $16.00 for.
How often should the impeller be changed?
There is no single interval in these sources. The Marine How To author changes theirs every spring regardless of condition and calls impellers cheap insurance, while noting that others see that as overkill. The same author says impellers do not follow a schedule, because running dry or a partial weed plug in the intake can kill one quickly.
Is the calculator figure an exact quote?
No. BoatCostCalc describes it as a planning range built from public source rows, to compare quoted scope rather than replace a marina estimate.
Why does a failed impeller cost so much more than a planned one?
Because the damage spreads. Marine How To says a thrown blade or an overheated engine can cost far more than the part, and fragments lodged in a hose, elbow or heat exchanger must be found and removed. Checking the old impeller for missing pieces is the step that protects the engine.
Related pages and posts
- Boat Engine Repair Cost: What Drives the Price and How to Get Accurate Estimates
- Boat Engine Repair Cost: Ranges by Engine Type and What Makes Them Vary
- Boat Winterization Checklist: Engine, Water Systems, and Storage
- Boat Deck Repair & Replacement in Richmond, CA | Boatwork
- Boat Detailing Near Me: Complete Cost Guide for South Florida Boat Owners | Boatwork
- Boat Canvas Patching: How to Decide Between Repair and Replacement
