Honda BF40 Water Pump Impeller Replacement
A worn impeller on your 40 hp Honda BF40 starves the engine of cooling water and can overheat it in minutes. Below is the exact water-pump kit that fits this engine, a step-by-step video, and the parts you need to do the job yourself.
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Watch: how to replace it (step by step)
How to Replace Impeller – Honda BF40
Honda 40hp Outboard Over Heating burnt Impeller. Holy Shit Why? I got a nest of Carpenter Ants !
Tools Needed
- Screwdriver
- Pliers
Safety
- Warning 1: Ensure the engine is cool before starting any work.
- Warning 2: Wear gloves to protect against any remaining ant debris.
Steps
- Turn off the engine and allow it to cool completely.
- Locate the screws securing the engine cover and remove them using a screwdriver.
- Carefully lift the engine cover off to expose the internal components.
- Inspect the impeller for any signs of damage or burning.
- If the impeller is damaged, use pliers to carefully remove it from the engine.
- Check for any remaining ant nests or debris inside the engine.
- Clean the engine thoroughly to remove any ant remnants.
- Install a new impeller, ensuring it is properly seated and secured.
- Replace the engine cover and secure it with the screws.
Tips
- Tip from the video: Check for ant nests during the winter to prevent damage.
- Another tip: Regularly inspect and maintain your engine to prevent overheating issues.
Which part do I need for my Honda BF40?
For most BF40 owners the part above (06193) is the right choice. Price tip: the aftermarket numbers are usually noticeably cheaper than the OEM-branded box — it is the same physical part. If you need an exact match, these compatible part numbers also fit:
Show all compatible part numbers (6)
| Part number | Description | |
|---|---|---|
| 18-3248 | Impeller for Honda BF40A | Find on Amazon → |
| 18-3282 | Impeller for Honda BF40A | Find on Amazon → |
| 19210 | Honda Impeller BF35 / BF40 / BF45 / BF50 / BF60 (19210-ZV5-003) | Find on Amazon → |
| 19233 | Honda Water pump Gasket BF35AM BF40B / B2 / BX / A4 / D / DK2 / A / A1 / 2 / AX / AY BF45AM BF25D4 / DK2 / A / A1 / AX / A2 / A3 BF30D4 / K2 / A / A1 / AX / AZ / A3 BF50A4 / D / DK2 / A / A1 / A2 / AX | Find on Amazon → |
| 19242 | Honda Water pump Gasket BF20A / AX / A2 BF35AM BF40B / B2 / BX / A4 / D / DK2 / A / A1 / A2 / AX / A3 / AY BF45AM BF25D4 / DK2 / A / A1 / AX / A2 / A3 BF50A4 / D / DK2 / A / A1 / A2 / A3 / AY BF30D4 / | Find on Amazon → |
| 90752 | Honda Impeller Key BF35 / BF40 / BF45 / BF50 / BF60 (90752-ZV5-003) | Find on Amazon → |
Many of these are the same physical part under different brand numbers. Confirm against your engine plate before ordering.
Frequently asked questions
What water pump impeller fits a Honda BF40 (40 hp)?
The Honda BF40 uses the impeller sold as 06193, plus its OEM and aftermarket cross-references (6 compatible numbers are listed above). Confirm the number against your engine's model code and year plate before ordering.
How often should I replace the impeller on a Honda BF40?
Replace the water pump impeller every 1-3 years or roughly every 200-300 running hours, whichever comes first — and sooner if you run in silty, sandy or shallow water.
What are the symptoms of a failing impeller on a Honda BF40?
A weak or missing telltale stream, engine temperature climbing above normal, or an overheat alarm are the classic warning signs. A worn impeller can overheat and damage the engine within minutes, so don't delay the job.
Do I need the full water pump kit or just the impeller?
For the BF40, fit the complete kit. The seals, O-rings, gasket and wear plate age alongside the impeller, and replacing them together is the reliable, do-it-once job.
How long does a water pump job take on a Honda BF40?
For a competent DIYer it's typically a 1-2 hour job of medium difficulty. The step-by-step video above covers every step.
Related guides
- Honda BF5 water pump / impeller
- Honda BF225 water pump / impeller
- All Honda water pump guides
- Free Honda boat valuation
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