Sierra Marine - Fuel Water Separator Filter - 18-7862
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The AP-1647 Fuel Water Separator Filter Element is a marine replacement filter element commonly cross-referenced with Sierra Marine 18-7862. It is designed for compatible marine fuel/water separator assemblies and helps protect outboard and marine fuel systems by reducing water and fine particulate contamination before fuel reaches the engine.
This is the replacement filter element only. It is not a spin-on canister, complete filter housing, mounting head, bracket, or full fuel/water separator assembly.
Key Features
- Marine replacement fuel/water separator filter element.
- Part number: AP-1647.
- Cross-reference: Sierra Marine 18-7862.
- Aqua Power / AP-style reference filter element.
- Designed for compatible marine fuel/water separator assemblies.
- Helps reduce water contamination in marine fuel.
- Helps trap fine particles before they reach the engine fuel system.
- Typical filtration rating: 20 micron.
- Supports protection of carburetors, injectors, fuel pumps, and high-pressure fuel components.
- Includes replacement sealing gasket where supplied.
Fuel System Compatibility
Common application context includes compatible marine fuel/water separator assemblies used with:
- Outboard marine engines.
- Marine gasoline fuel systems.
- Fuel/water separator units that call for AP-1647, Sierra 18-7862, or a verified equivalent element.
- Ethanol-blended fuel systems where water separation and particulate filtration are required.
- Seasonal service replacement on compatible boat fuel systems.
Use this element only where the separator assembly, gasket, fuel type, and engine fuel-flow requirement match the original application.
Fitment Notice
Confirm fitment by matching the existing element number, separator assembly design, gasket size, fuel type, and engine fuel-flow requirement before ordering. This part is not a universal filter housing and will only fit compatible assemblies designed for this style of replacement element.
When This Part Needs Replacement
Replace the fuel/water separator element during routine seasonal service, after contaminated fuel exposure, after water is found in the fuel system, or when the engine shows signs of fuel restriction or contamination such as hard starting, rough idle, hesitation, surging, stalling, or loss of power under load.
Replacement is also recommended any time the element is damaged, clogged, fuel-soaked beyond normal service condition, or past the engine manufacturer's recommended service interval.
Installation Notes
Shut off the fuel supply before servicing the fuel/water separator. Remove the old element according to the separator assembly instructions and inspect the gasket and sealing surfaces. Clean the housing or assembly area before installing the new element.
Install the replacement element and gasket as specified for the separator assembly. After service, prime the fuel system, check carefully for leaks, and run the engine while inspecting all fuel connections.
Dispose of the used fuel filter element and contaminated fuel according to local environmental requirements.
Alternate / Cross-Reference Part Numbers
- AP-1647 — primary supplied part number
- Sierra Marine 18-7862 — cross-reference
- 18-7862 — common marine fuel filter element reference
- Aqua Power AP-1647 — alternate brand/reference format
Parts Desk Insight
This part should be listed clearly as a replacement filter element, not as a spin-on filter or complete fuel/water separator housing. For best results, customers should compare the old element and gasket to confirm the correct replacement before installation. Fuel system protection depends on both the correct filter element and a clean, properly sealed separator assembly.
Shipping: Ships same or next day for fast Canada wide shipping. ⚓
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.