Sierra 18-7831 Inline Fuel Filter, 3/8 Inch, Replaces Mercury 802128A1 and OMC 398319

The Sierra 18-7831 is an inline fuel filter built for outboard and personal watercraft fuel systems that require a 3/8 inch (9.5mm) inline filter. It uses a durable plastic outer housing and is designed as a direct replacement for the OEM fuel filters used by Mercury Marine and OMC-equipped outboards, making it a straightforward swap during routine fuel system maintenance. The filter is intended to protect carburetors and fuel injection components from debris and contaminants in the fuel line, helping maintain consistent fuel flow and engine performance.

This filter is cross-referenced to several widely used aftermarket and OEM part numbers, so it is compatible with equipment originally fitted with Fram, GLM, Mallory, OMC, or Wix filters bearing the matching part numbers listed below. Each unit ships as a single filter (1 count) ready for installation in the fuel line.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-7831
• Item Type: Fuel Filter
• Style: In-Line
• Size: 3/8 inch (9.5 millimeters)
• Item Diameter: 9.5 Millimeters
• Outer Material: Plastic
• Vehicle Service Type: Personal Watercraft
• Weight: 0.08 pounds
• UPC: 808282368920
• Unit Count: 1

Fitment

Designed for outboard and personal watercraft fuel systems that use a 3/8 inch (9.5mm) inline fuel filter, including applications originally equipped with the OEM and aftermarket filters listed below.

Replaces (OEM)

• Fram G15
• Fram G3
• GLM 40160
• Evinrude/Johnson 398319
• Mallory 9-37960
• Mercury Marine 802128A1
• Mercury 802128
• OMC 3852224
• OMC 398319
• Wix 33033

Frequently Asked Questions

What size is the Sierra 18-7831 fuel filter? The Sierra 18-7831 is a 3/8 inch (9.5mm) inline fuel filter, sized to fit fuel lines using that standard diameter.

What OEM part numbers does the 18-7831 replace? This filter is a cross-reference match for Mercury Marine 802128A1 and 802128, OMC 398319 and 3852224, Fram G15 and G3, GLM 40160, Mallory 9-37960, and Wix 33033, so it can be installed anywhere those numbers are specified.

Is the Sierra 18-7831 an OEM part or an aftermarket replacement? It is an aftermarket fuel filter manufactured by Sierra that cross-references directly to the Mercury Marine 802128A1 and OMC 398319 OEM part numbers, allowing it to be used in place of the original filter.

What material is the 18-7831 fuel filter housing made of? The housing is made of plastic, which is the outer material used for the Sierra 18-7831 inline fuel filter.

How many filters come in one order of the 18-7831? Each order includes one Sierra 18-7831 fuel filter (unit count of 1).

What is the weight of the Sierra 18-7831 fuel filter? The Sierra 18-7831 weighs 0.08 pounds.

Will the Sierra 18-7831 fit my Evinrude or Johnson outboard? Yes, the 18-7831 cross-references to Evinrude/Johnson part number 398319, making it compatible with fuel systems that call for that filter.

Can the 18-7831 be used on a personal watercraft? Yes, the Sierra 18-7831 inline fuel filter is designated for personal watercraft fuel system use in addition to outboard applications.

Is the Sierra 18-7831 the same filter as the Fram G3? The 18-7831 is cross-referenced to the Fram G3 and Fram G15, meaning it is designed to be a functional equivalent for fuel systems specifying either of those Fram filters.

How is the 18-7831 fuel filter installed? As an inline 3/8 inch fuel filter, the Sierra 18-7831 installs directly into the fuel line at the point where the existing inline filter is located, in place of the OEM or cross-referenced filter it replaces.