Aqua Power Fuel/Water Separating Filter AP-6012

The Sierra / Aqua Power AP-6012 Fuel Water Separating Filter, commonly cross-referenced with Sierra Marine 18-7846, is a heavy-duty marine replacement filter element designed for compatible fuel/water separator heads. It helps remove water and capture sediment from marine fuel before it reaches the engine fuel system.

This filter is intended for high-demand marine fuel systems where the existing filter head, thread size, flow requirement, and application call for AP-6012, Sierra 18-7846, or a verified equivalent.

Key Features

• Marine fuel/water separating replacement filter.
• Part number: AP-6012.
• Cross-reference: Sierra Marine 18-7846.
• Designed for compatible marine fuel/water separator filter heads.
• Helps separate water from marine fuel.
• Helps capture sediment and fine particulate contamination.
• Typical filtration rating: 21 micron.
• Flow reference: up to 90 GPH where the fuel system and filter head support that rating.
• Thread reference: 1 in.-12.
• Approximate canister height: 4.3 in.
• Epoxy-coated canister helps resist corrosion in damp marine environments.
• Suitable for compatible gasoline marine fuel systems using ethanol-blended fuel where this filter style is specified.

Fuel System Compatibility

Common application context includes compatible marine fuel/water separator systems used with:

• High-horsepower outboard engines.
• Inboard gasoline engines.
• Sterndrive fuel systems.
• Commercial and recreational vessel fuel systems.
• Marine fuel filter heads requiring a 1 in.-12 threaded replacement filter.
• Applications where AP-6012, Sierra 18-7846, or an approved equivalent is listed.

Use this filter only where the filter head, thread size, gasket fit, fuel type, flow requirement, and engine manufacturer’s service information confirm compatibility.

Fitment Notice

Confirm fitment by matching the existing filter part number, filter head thread, gasket diameter, canister clearance, fuel type, and required fuel-flow capacity before ordering. Marine fuel/water separating filters can look similar but differ in thread size, gasket fit, canister height, micron rating, and flow capacity.

This is a replacement filter only. It does not include the filter head, mounting bracket, fittings, fuel hose, primer components, or complete separator assembly.

When This Part Needs Replacement

Replace the filter during routine seasonal fuel-system service, after contaminated fuel exposure, after water is found in the fuel system, or when the engine shows signs of fuel restriction such as hard starting, rough idle, hesitation, surging, loss of power, or stalling under load.

Replacement is also recommended if the filter canister is rusted, dented, leaking, clogged, or past the service interval recommended for the engine and fuel system.

Installation Notes

Shut off the fuel supply before servicing the fuel/water separator. Place absorbent material under the filter, remove the old filter, and confirm the old gasket is not stuck to the filter head. Clean the sealing surface before installation.

Lightly lubricate the new gasket with clean fuel or engine oil, install the filter by hand, and tighten according to the filter head or engine service instructions. Do not over-tighten. After installation, prime the fuel system, check carefully for leaks, and run the engine while inspecting all fuel connections.

Dispose of the used filter and any contaminated fuel according to local environmental requirements.

Alternate / Cross-Reference Part Numbers

• AP-6012 primary supplied part number
• Sierra Marine 18-7846 cross-reference reference
• Crusader 98041 cross-reference reference; verify by application
• Johnson / Evinrude 502905 cross-reference reference; verify by application
• Quicksilver 8M0061975 cross-reference reference; verify by engine serial number
• Mallory Marine 9-37803 cross-reference reference; verify by application
• GLM 24930 cross-reference reference; verify by application

Parts Desk Insight

For marine fuel filters, the most important checks are the filter head thread, gasket fit, flow rating, and fuel-system requirement. A higher-flow filter still needs to match the existing separator head correctly to seal and perform properly. If water is found in the filter, inspect the fuel tank and fuel supply as well, not just the filter element.

Shipping: Ships same or next day for fast Canada wide shipping.