Attwood Marine Fuel/Water Separator, 10 Micron, Double Seal

Overview

The Attwood Marine Fuel/Water Separator is a 10-micron marine fuel filtration range for helping remove water and fine contaminants before fuel reaches a 2-cycle or 4-cycle engine. It is made for boats that need a serviceable fuel/water separator setup in the fuel line, especially where moisture in the tank or fuel supply can lead to rough running, poor starts, or avoidable carburetor and injector issues.

The range includes a universal separator kit with a mounting bracket and a replacement canister option. The assembly uses universal 3/8-inch ports and a double-seal configuration, giving installers a straightforward way to add or service a separator on many outboard and small-boat fuel systems.

Key features

• 10-micron filtration helps trap water and fine fuel contaminants before they move farther through the fuel system.
• Supports 2-cycle and 4-cycle marine engine applications when the vessel is matched to this separator style.
• Universal 3/8-inch ports on the assembly suit common marine fuel-line layouts.
• Double-seal configuration helps the filter seat securely during service.
• Universal kit configuration includes the filter, mounting bracket, and brass plugs for a complete separator installation.
• Replacement canister configuration supports routine maintenance of an existing compatible separator assembly.

Variants

This product is offered in two configurations: a universal fuel/water separator kit and a replacement fuel/water separator canister. Both are part of the same Attwood fuel filtration family, but they serve different maintenance and installation needs on board.

The main difference is whether the boat needs a complete separator kit with mounting hardware or only the replacement canister for an existing compatible setup. The 10-micron filtration and double-seal design are consistent across the range.

• 11840-7: Universal Fuel/Water Separator. This is the kit version for adding or replacing a full separator setup, with the filter, bracket, and two brass plugs included for installation.
• 11841-4: Fuel/Water Separator. This is the replacement canister for servicing a compatible separator assembly without replacing the bracket setup.

Installation and setup

Mount the separator where it can be reached for inspection and filter changes, while keeping it protected from direct impact and excessive bilge water exposure. The 3/8-inch ports make it easier to integrate with common marine fuel hose arrangements, but the fuel line, clamps, and routing should always match the vessel’s fuel-system requirements.

On small fishing boats, runabouts, and coastal cruising boats, this style of separator is commonly fitted between the fuel tank and engine. Leave enough clearance below and around the canister so routine replacement does not turn into a tight engine-well job.

Maintenance and use on board

A fuel/water separator is a practical service item, not a fit-and-forget part. Check it as part of seasonal commissioning, after questionable fuel fills, and before longer runs where fuel contamination would be more than a dockside inconvenience.

This product is a good match for boat owners maintaining outboard and small-boat fuel systems who want a simple separator setup with a known 10-micron rating and an available replacement canister for future service.