Suzuki DF20 Water Pump Impeller Replacement
A worn impeller on your 20 hp Suzuki DF20 starves the engine of cooling water and can overheat it in minutes. Below is the water-pump kit we recommend, which DF20 variants it fits, a step-by-step video, and the parts you need to do the job yourself.
Check today’s price on Amazon →
Watch: how to replace it (step by step)
How to replace the water pump impeller on a Suzuki DF20
Suzuki DF20A 2017 2018 Outboard Impeller Oil Filter Plug Change Thermostat & Internal Anode Location
Tools Needed
- 12mm socket wrench
- Allen key (size not specified)
- Clamps
- Gear oil or gear lube pump
- New impeller and gasket
Safety
- Ensure the engine is off and the kill cord is not in place before starting any work.
- Wear gloves when handling gear oil to avoid staining your hands.
Steps
- Remove the bolts securing the leg to the engine using a 12mm socket wrench.
- Detach the gear lever by undoing the top knot and moving the gear lever if necessary.
- Tilt the engine to access and remove the leg.
- Secure the engine to a bench using clamps to prevent it from kicking out.
- Remove the old impeller by unscrewing the key and popping it out.
- Inspect the old impeller for damage; if it's still in good condition, save it for emergencies.
- Install the new impeller by aligning the pin with the slot and securing it in place.
- Apply a small amount of grease to the nuts to prevent seizing.
- Tighten the nuts securing the impeller, ensuring they are not overtightened.
- Allow the engine to settle for a short period before checking the impeller installation.
- Drain the gear oil by removing the screw at the bottom and allowing air to enter through the top screw.
- Refill the gear oil using a gear oil or gear lube pump, ensuring it is filled to the correct level.
- Reinstall the screws and remove any excess gear oil.
- Drain the engine oil by removing the Allen key fitting at the bottom of the engine.
- Remove the cowling by undoing the screws on the side, lowering it out of the way.
- Remove the oil filter by taking off the plate and replacing the o-ring if necessary.
- Install the new oil filter and reattach the cowling, ensuring the rubber gasket fits correctly between the plastic slots.
- Refill the engine with 10w40 oil, as recommended by the speaker.
Tips
- Do not overtighten nuts and bolts to prevent seizing and potential damage.
- Inspect and replace the impeller every two years for optimal engine performance.
- Save old, undamaged impellers for emergency use.
Which part do I need for my Suzuki DF20?
For most DF20 owners the part above (15220) 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 (2)
| Part number | Description | Fits | |
|---|---|---|---|
| 16750 | Water Pump Cup | DF20A (2013–2025) | cross-reference only |
| 89647 | Impeller | DF20A (2013–2025) | cross-reference only |
Many of these are the same physical part under different brand numbers. Build years are shown where our parts data has them. Where a variant has no years, only the model code is listed. Confirm against your engine plate before ordering.
Frequently asked questions
What water pump impeller fits a Suzuki DF20 (20 hp)?
Our parts catalogue lists the Suzuki DF20 impeller as 15220, an internal reference no retailer stocks. 2 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 Suzuki DF20?
On the DF20 the guidance in the video is to replace it every two years, whichever comes first — and sooner if you run in silty, sandy or shallow water.
What are the symptoms of a failing impeller on a Suzuki DF20?
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 DF20, 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 Suzuki DF20?
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
- Suzuki DF15 water pump / impeller
- Suzuki DF40 water pump / impeller
- Suzuki DF60 water pump / impeller
- Suzuki DF4 water pump / impeller
- All Suzuki water pump guides
- Free Suzuki boat valuation
- Buying a boat? Check whether the asking price is fair
As an Amazon Associate we earn from qualifying purchases — at no extra cost to you. Prices and availability are shown at checkout. This guide is for reference; always follow the engine manufacturer’s service manual.