Yamaha F90 Oil & Filter Change
Fresh oil and a new filter are the cheapest insurance for your 90 hp Yamaha F90. Below is the oil filter we recommend, which F90 variants it fits, a step-by-step video of the full oil change, and what else you need for the job.
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Watch: how to do it (step by step)
How to replace the oil filter on a Yamaha F90
How To: Oil Change & Lower Unit service on Yamaha F90 Four Stroke outboard
Oil Change & Lower Unit Service Guide for Yamaha F90 Four Stroke Outboard
Tools Needed
- Oil change kit (including oil filter, oil, and funnel)
- 14mm socket wrench
- Phillips screwdriver (large blade)
- Lower unit gear oil pump kit
- Waste basket
- Ear muffs (for starting the motor)
Safety
- Warm up the motor before starting to allow oil to drain quickly.
- Be cautious when removing and reinstalling the cowling.
Steps
- Warm up the outboard motor for 5 minutes with ear muffs on.
- Remove the cowling by releasing the snaps at the back and front.
- Tilt the motor up to prevent oil from gushing out.
- Unscrew the oil drain bolt using a 14mm socket wrench.
- Place a container underneath to catch the draining oil.
- Allow the oil to drain completely, switching containers if necessary.
- Remove the oil fill cap to release pressure and allow all oil to flow out.
- Clean up any mess from the oil drain process.
- Remove the old oil filter by unscrewing it with your hands or using a wrench.
- Install the new oil filter, applying a small amount of oil around the edge for better sealing.
- Screw on the new oil filter by hand until tight.
- Pour the recommended amount of fresh oil into the motor through the oil fill hole using a funnel.
- Replace the oil fill cap and start the motor to circulate the new oil.
- Let the motor run for a few minutes, then tilt it up for 5 minutes to allow the oil to settle.
- Turn off the motor and let it sit upright for another 5 minutes before checking the oil level.
- Drain the lower unit gear oil by removing the bottom plug with a large Phillips screwdriver and releasing pressure from the top screw.
- Allow the gear oil to drain completely, then clean up any mess.
- Use the lower unit gear oil pump kit to force new gear oil into the bottom of the lower unit, pushing out any air bubbles.
- Once the gear oil reaches the top air breather hole, seal both the top and bottom plugs.
- Start the motor and let it run briefly to ensure proper operation.
Tips
- Use at least three containers for draining oil to avoid spills.
- Keep an eye on the oil level after adding new oil to ensure it's within the correct range.
- Verify that there are no water or other substances in your oil and lower unit gear oil during servicing.
Which part do I need for my Yamaha F90?
For most F90 owners the part above (18-7911-1) 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 (1)
| Part number | Description | Fits | |
|---|---|---|---|
| 3R0-07615-0 | Oil filter | F90 | 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 oil filter fits a Yamaha F90 (90 hp)?
The Yamaha F90 uses the oil filter sold as Sierra 18-7911-1, plus its OEM and aftermarket cross-references (1 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 oil filter on a Yamaha F90?
Change the oil and filter every 100 running hours or once a season, whichever comes first (check your manual for the exact interval).
What else do I need for an oil change on a Yamaha F90?
The correct grade and amount of engine oil (see the manual or the video), a new drain-plug washer, a filter wrench and a drain pan or oil extractor pump. Nothing exotic — it is standard service equipment.
What are the signs the oil is overdue on a Yamaha F90?
Dark, gritty oil well past its interval, low-pressure warnings — and milky or grey oil, which means water is getting in and should be investigated immediately.
How long does an oil change take on a Yamaha F90?
About an hour for a competent DIYer. Run the engine warm first — warm oil drains faster and carries more contaminants out with it.
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