Mercury 40 HP Fuel Filter Replacement
A clogged fuel filter starves your 40 hp Mercury 40 HP of fuel — hard starts, hesitation and lost power at speed. Below is the exact filter that 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 Fuel Filter – Mercury F60 Efi
In-Line Fuel Filter Change Mercury 40/50/60 hp EFI
Tools Needed
- Shop towels
- Zip tie (optional)
Safety
- Be cautious when removing the zip tie to avoid losing it in the motor.
- Expect residual fuel to leak out when disconnecting the fuel filter.
Steps
- Locate the high-pressure inline fuel filter, which is covered by a sleeve secured with a zip tie.
- Carefully remove the zip tie and slide the sleeve off the fuel filter.
- Disconnect the first portion of the fuel line by pushing the red clip and sliding the sleeve off.
- Disconnect the second portion of the fuel line in the same manner.
- Remove the old fuel filter from the motor.
- Inspect the old fuel filter for any contamination by cutting it open.
- Install the new fuel filter, ensuring the arrow points toward the back of the motor.
- Attach the first section of the fuel line, clipping it into place.
- Reattach the sleeve and the second section of the fuel line, clipping it into place.
- Secure the fuel filter with a zip tie and collar.
- Clean up any excess fuel with shop towels.
Tips
- Replace the inline fuel filter every 100 hours or annually, even if the fuel appears clean.
- Inspect the old fuel filter for contamination to ensure proper maintenance.
Which part do I need for my Mercury 40 HP?
For most 40 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 (8)
| Part number | Description | |
|---|---|---|
| 18-7750-1 | Sierra 18-7750-1 | Find on Amazon → |
| 18-7914 | Fuel Filter for Mercury, Johnson/Evinrude and Suzuki engines. | Find on Amazon → |
| 35-822626Q2 | Mercury OEM 35-822626Q2 (replaces Sierra 18-7914) | Find on Amazon → |
| Johnson/Evinrude 778885, 5031411 | Fuel filter | Find on Amazon → |
| K04 | Mercury OEM K04 (replaces Sierra 18-7914) | Find on Amazon → |
| Mercury 35-822626Q2, 35-822626Q04 | Fuel filter | Find on Amazon → |
| Q04 | Mercury OEM Q04 (replaces Sierra 18-7914) | Find on Amazon → |
| Suzuki 16510-87J00 | Fuel filter | 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 fuel filter fits a Mercury 40 HP (40 hp)?
The Mercury 40 HP uses the fuel filter sold as 18-3057, plus its OEM and aftermarket cross-references (8 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 40 HP?
On the 40 HP the guidance in the video is to replace it every 100 hours.
What are the symptoms of a clogged fuel filter on a Mercury 40 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 40 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 30 HP fuel filter
- Mercury 60 HP fuel filter
- All Mercury maintenance guides
- Free Mercury boat valuation
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