Mercury 30 HP Fuel Filter Replacement
A clogged fuel filter starves your 30 hp Mercury 30 HP of fuel — hard starts, hesitation and lost power at speed. Below is the filter we recommend, which 30 HP variants it fits, a step-by-step video, and the symptoms to look for.
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Watch: how to do it (step by step)
How to replace the fuel filter on a Mercury 30 HP
Mercury 30HP EFI 4 Stroke – Fuel Filter Install – Lowe Skorpion
Tools Needed
- Half-inch wrench
- 10mm wrench
- Different hose clamps
- Different washer and nut
Safety
- Ensure the engine is turned off and cool before starting.
- Be cautious when handling fuel lines to avoid spills.
Steps
- Remove the cover to access the fuel filter.
- Use a half-inch wrench to loosen the bolt that secures the filter.
- Remove the tabs from the fuel lines to free up the filter.
- Slide the hoses up, noting that the plastic might be thicker, requiring different hose clamps.
- Install the new filter by sliding it into position.
- Use a 10mm wrench to secure the filter with a different washer and nut if needed.
- Reinstall the cover and start the boat to ensure it runs properly for about 15 minutes.
- Turn the water back on and check if the boat starts.
Tips
- The new filter might be a different version, so be prepared to use different hose clamps and securing hardware.
- Allow the boat to run for a sufficient amount of time to ensure the new filter is working properly.
Which part do I need for my Mercury 30 HP?
For most 30 HP owners the part above (18-3057) 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 (7)
| Part number | Description | Fits | |
|---|---|---|---|
| 18-7750-1 | Sierra 18-7750-1 | 30 | Find on Amazon → |
| 18-7914 | Fuel Filter for Mercury, Johnson/Evinrude and Suzuki engines. | 30HP | Find on Amazon → |
| 35-822626Q2 | Mercury OEM 35-822626Q2 (replaces Sierra 18-7914) | 30HP | Find on Amazon → |
| 778885 | Fuel filter | 30HP | Find on Amazon → |
| 5031411 | Fuel filter | 30HP | Find on Amazon → |
| 35-822626Q04 | Fuel filter | 30HP | Find on Amazon → |
| 16510-87J00 | Fuel filter | 30HP | Find on Amazon → |
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 fuel filter fits a Mercury 30 HP (30 hp)?
The Mercury 30 HP uses the fuel filter sold as Sierra 18-3057, plus its OEM and aftermarket cross-references (7 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 fuel filter on a Mercury 30 HP?
Replace the fuel filter once a season or per the service manual — and sooner after a batch of dirty fuel or water in the separator.
What are the symptoms of a clogged fuel filter on a Mercury 30 HP?
Hard starting, hesitation or surging under load, stalling at higher throttle and a general loss of power. The engine typically runs fine at idle and starves when fuel demand rises.
Do I need to bleed or prime the fuel system afterwards?
On diesel engines, yes — air must be bled from the fuel system after the filter change, and the video shows the procedure. On petrol outboards, squeeze the primer bulb firm before starting.
How long does a fuel filter change take on a Mercury 30 HP?
Usually 30-60 minutes including priming or bleeding — a straightforward DIY job with basic tools.
Related guides
- Mercury 115 HP fuel filter
- Mercury 75 HP fuel filter
- Mercury 40 HP fuel filter
- Mercury 60 HP fuel filter
- All Mercury maintenance guides
- Free Mercury boat valuation
- Buying a boat? Check whether the asking price is fair
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