Fuel Filter Kit – Fits MerCruiser 2.5L, 3.0L, 3.7L, 4.3L Sterndrive Engines (Replaces 803897Q1, 8M0046752)

Fuel Filter Kit – Fits MerCruiser 2.5L, 3.0L, 3.7L, 4.3L Sterndrive Engines

This fuel filter kit is designed for a wide range of MerCruiser 4-stroke sterndrive engines, including 2.5L (120 HP), 3.0L (140 HP), 3.7L (165-190 HP), and 4.3L (V6) models manufactured from the 1980s through the 2000s. It serves as a direct-fit replacement for the filter located inside the mechanical fuel pump.

It directly replaces OEM part numbers including MerCruiser 35-803897Q1, 8M0046752, 35-8M0046752, 803897K1, Sierra 18-7784, Mallory 9-37821, and Volvo Penta 3855104, ensuring compatibility and reliable performance.

• Complete Service Kit: Includes the filter element, a new spring, and multiple rubber gaskets to ensure a leak-free seal.
• Installation Location: Designed for installation inside the mechanical fuel pump's lower canister.
• Fuel Compatibility: Engineered for use with gasoline fuel systems.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Confirm your engine model/year in the table below.

Technical Specifications

Package Contents

• 1 x Filter Element
• 1 x Spring
• 3 x Rubber Rings/Gaskets

Installation Guide

1. Ensure the engine is off and cool, and disconnect the battery for safety.
2. Locate the mechanical fuel pump, typically mounted on the engine block.
3. Place a rag or small container under the pump to catch any gasoline that may spill.
4. Carefully unscrew the downward-facing cap or canister at the bottom of the fuel pump.
5. Remove the old filter element, spring, and any existing rubber gaskets. Note their order and orientation.
6. Wipe the inside of the pump canister clean of any debris or sediment.
7. Select the correct new rubber gasket from the kit and place it on the canister or pump housing.
8. Insert the new spring and filter element into the canister.
9. Securely reinstall the canister, tightening it by hand until snug. Do not overtighten.
10. Reconnect the battery.
11. Prime the fuel system according to your engine's manual and carefully inspect for any leaks before starting the engine.

Troubleshooting & FAQ

Q: How do I confirm this filter fits my MerCruiser engine?

A: Check your engine's serial number. This kit is specified for 2.5L & 3.0L models with s/n 6229718 & later, 3.7L models with s/n 6916779 & later, and 4.3L GM engines with s/n 0A331455 & later that use a Carter-style mechanical fuel pump. Cross-referencing your old filter's part number with our list (e.g., 35-803897Q1) is the best way to guarantee fitment.

Q: Where is this filter located on the engine?

A: This filter element is not a standalone canister. It is designed to be installed inside the lower canister of the engine's mechanical fuel pump.

Q: What are the signs my fuel filter needs replacement?

A: Common symptoms of a clogged filter include engine hesitation, sputtering, loss of power (especially at high RPMs), difficulty starting, or stalling. A periodic visual inspection during maintenance can also reveal a dirty element.

Q: What is included in this kit?

A: The kit is a complete service package, containing the filter element, a new installation spring, and three assorted rubber rings/gaskets to ensure you have the correct seal for your specific fuel pump model.

Q: OEM vs. Aftermarket?

A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?

A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?

A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.