Seachoice 21003 Full-Flow Oil Filter
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
The Seachoice 21003 is a full-flow spin-on oil filter for compatible Honda, Yamaha, and Nissan/Tohatsu marine outboard engines. It is a direct replacement for Sierra 18-7911-1 and multiple OEM part numbers, and is manufactured in an ISO/TS 16949 certified facility to meet or exceed OEM specifications.
The 20-micron cellulose filter element captures large contamination particles before they can reach lubricated engine components, while maintaining low restriction for full oil flow. An epoxy-coated canister resists corrosion in the marine environment, and a thicker body wall improves structural integrity under pressure. Heavy-duty end cap seals reduce the risk of leakage, and an anti-drain back valve prevents oil from draining out of the filter when the engine is off — ensuring immediate oil pressure on start-up.
- Full-flow spin-on oil filter
- 20-micron cellulose filter element
- Anti-drain back valve — maintains oil in filter between starts
- Epoxy-coated canister for corrosion resistance
- Thicker body wall for improved structural integrity
- Heavy-duty end cap seals
- Manufactured in an ISO/TS 16949 certified facility
Replaces:
- Sierra: 18-7911-1
- Honda: 15400-PFB-007
- Nissan / Tohatsu: 3R0-07615-0
- Yamaha: 5GH-13440-00-00
Best Use Case: A direct service replacement for the oil filter on compatible Honda, Yamaha, and Nissan/Tohatsu outboard engines during routine oil changes. Confirm your engine model and current filter part number against the cross-reference list above before ordering.
Parts Desk Insights: Always verify fitment using your engine’s current OEM filter part number — outboard manufacturers use different filters across their engine range and the cross-reference list above covers specific models only. For Mercury and MerCruiser engine oil filters, see the Seachoice 21004 Full-Flow Oil Filter. For cartridge-style filter elements, see the Seachoice 21008 Full-Flow Oil Filter (Element) and the Seachoice 21016 Full-Flow Oil Filter (Element). Replace the oil filter at every oil change — reusing a filter is not recommended even if it appears clean.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.