Sierra Fuel Filter 18-7784, Replaces 35-803897Q1 / 35-11004A1, for Mercruiser MCM 120/2.5L, 140/3.0L, 3.7L, 3.8L & 4.3L Engines

The Sierra 18-7784 is a marine fuel filter engineered for Mercruiser stern drive engines, built to trap contaminants before they reach the carburetor or fuel injection system and protect the engine from debris-related damage. It carries a 20 micron rating, filtering fine particulate from the fuel stream while maintaining steady flow to the engine. The filter's outer body is stainless steel, chosen for its resistance to corrosion in the harsh marine environment where constant exposure to moisture, salt air, and fuel vapors quickly degrades lesser materials.

This filter is designed to fit Mercruiser MCM 120/2.5L, 140/3.0L/LX, 3.7L, 3.8L, and 4.3L engines. Sierra manufactures this part to meet or exceed the specifications of the original equipment it replaces, and it is built as a direct equivalent for the OEM Mercury Marine part numbers it cross-references. As with all Sierra marine parts, it is produced to stand up to continuous duty in a boat's fuel system rather than an automotive one, where vibration, humidity, and fuel formulation differ from typical land use.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-7784
• Product Type: Marine Fuel Filter
• Micron Rating: 20 microns
• Outer Material: Stainless Steel
• Vehicle Service Type: Boat
• Weight: 0.06 pounds
• Unit Count: 1
• OEM Equivalent Part Number: 35-803897Q1, 35-11004A1
• UPC: 808282106126

Fitment

• Mercruiser MCM 120/2.5L
• Mercruiser MCM 140/3.0L/LX
• Mercruiser 3.7L
• Mercruiser 3.8L
• Mercruiser 4.3L

Replaces (OEM)

• 35-803897Q1
• 35-11004A1 (Mercury Marine)

Frequently Asked Questions

What engines does the Sierra 18-7784 fuel filter fit? The Sierra 18-7784 is designed for Mercruiser MCM 120/2.5L, 140/3.0L/LX, 3.7L, 3.8L, and 4.3L engines.

What is the micron rating of this fuel filter? 20 microns is the filtration rating for the Sierra 18-7784 marine fuel filter.

What OEM part numbers does the 18-7784 replace? It cross-references to Mercury Marine OEM part numbers 35-803897Q1 and 35-11004A1.

Is the Sierra 18-7784 a genuine Mercury Marine part or aftermarket? The 18-7784 is a Sierra-manufactured replacement part, built to meet or exceed the specifications of the original Mercury Marine equipment it replaces rather than being a Mercury Marine branded part.

How much does the fuel filter weigh? The Sierra 18-7784 weighs 0.06 pounds.

What material is the filter housing made of? Stainless steel forms the outer body of the Sierra 18-7784, giving it corrosion resistance for marine use.

How many filters come in one package? One Sierra 18-7784 fuel filter is included per unit.

Can this filter be used in a car or automotive fuel system? No, the Sierra 18-7784 is built and rated for boat fuel systems (Vehicle Service Type: Boat), not automotive applications.

Does the 18-7784 fit the Mercruiser 3.0L engine? Yes, the Sierra 18-7784 fits the Mercruiser 140/3.0L/LX engine along with the 120/2.5L, 3.7L, 3.8L, and 4.3L models.

What is the UPC for this Sierra fuel filter? The UPC listed for the Sierra 18-7784 fuel filter is 808282106126.