5/16-Inch Inline Fuel Filter for Outboard Engines – Replaces Mercury Marine 35-816296Q2 and Sierra 18-7830

Product Details

This 5/16-inch inline fuel filter is an aftermarket replacement for fuel systems using a 5/16-inch fuel line. Installed inline beneath the outboard engine cowling, it helps remove fuel-system contaminants before they reach the engine.

The filter is listed as a replacement for Mercury Marine 35-816296Q2 and is cross-referenced with Sierra 18-7830. Reference catalogs also associate Sierra 18-7830 with Mercury Marine 35-134301, 35-164941, 35-816296-1, 35-8162961, 35-816296B1, 35-816296B2, 35-816296Q2, 35-816296T1, OMC 398327, and Yamaha 65W-24251-10-00.

• Inline installation for convenient access during service.
• Designed for fuel systems using a 5/16-inch line connection.
• Barbed hose connections for standard fuel-hose installation.
• Suitable for gasoline fuel systems when the filter dimensions and connection size match the original part.

Part Number Matrix

Use the following documented reference numbers to compare this filter with the part being replaced. Confirm the hose size, filter configuration, and application before ordering.

Engine and Application Compatibility

This replacement is intended for outboard fuel systems that use the documented reference filter and a 5/16-inch fuel-line connection. The reference material does not establish one universal horsepower, year, serial-number, or stroke range for every engine using these numbers.

Before installation, compare the original filter with the replacement and verify all of the following:

• The original filter is identified by one of the reference numbers in the matrix.
• The fuel hose has a 5/16-inch inside diameter.
• The replacement filter has the same flow direction and compatible hose connections.
• The engine model, year, serial number, and fuel-system requirements agree with the applicable manufacturer service information.

Technical Specifications

Product Type

Inline fuel filter

Fuel Type

Gasoline

Connection Size

5/16-inch fuel line

Installation

Inline in the fuel hose, typically beneath the outboard engine cowling

Connection Style

Barbed hose connections

Thread Size

Not applicable; non-threaded filter

Replacement Reference

Mercury Marine 35-816296Q2; Sierra 18-7830

Construction

Plastic inline filter housing

What’s in the Box

• 1 x Inline fuel filter

Hose clamps are not included unless specifically shown or stated in the order contents. Reuse suitable clamps only if they remain in good condition, or install new marine-appropriate fuel-hose clamps as required.

Installation Notes

1. Turn off the engine, allow it to cool completely, and work in a well-ventilated area away from ignition sources.
2. Locate the existing inline filter in the fuel line, usually beneath the engine cowling.
3. Place an absorbent pad or suitable container beneath the filter to catch residual fuel.
4. Release the existing clamps and carefully remove the fuel hoses from the old filter.
5. Note the flow-direction arrow on the original filter before removal.
6. Install the replacement with the flow arrow pointing toward the engine.
7. Push the fuel hoses fully onto the barbed connections and secure them with suitable fuel-hose clamps.
8. If equipped with a primer bulb, operate it to fill the filter and inspect every connection for leaks.
9. Start the engine only after confirming that no fuel is leaking, then inspect the connections again while the engine is running.

Troubleshooting and FAQ

Safety and Important Information

• Fuel is flammable. Keep the work area ventilated and away from flames, sparks, hot surfaces, and smoking.
• Do not install this filter if the hose size, connection style, flow direction, or original-part configuration does not match.
• Inspect all hoses and clamps during installation and repair any damaged fuel-system components before operating the engine.
• Professional installation is recommended when fuel-system service procedures or engine fitment are uncertain.
• This is an aftermarket replacement, not an OEM component.

About Sea Sierra

• Marine Replacement Parts — Practical aftermarket components for routine marine maintenance and repair.
• Fitment-Focused Information — Reference numbers and connection details are provided to help compare the replacement with the original part.
• Service-Ready Design — Inline installation supports straightforward inspection and replacement when the application is confirmed.