8M0149929 Service Kit for Mercury V6 V8 | JLM Marine

8M0149929 Service Kit for Mercury V6 V8

This comprehensive service kit is designed for Mercury V6 and V8 outboard engines, specifically the 175-300 HP models with 3.4L V6 and 4.6L V8 displacements. Engineered to meet OEM specifications, this kit provides all essential maintenance components to keep your engine running at peak performance.

This service kit directly replaces Mercury OEM part number 8M0149929, offering a complete maintenance solution in one convenient package. It includes premium-quality oil and fuel filters, lower unit drain gaskets, and a gear oil pump—everything needed for thorough routine service.

• Complete service solution with oil filter, fuel filter, drain gaskets, and gear oil pump
• Fits Mercury V6 (3.4L) and V8 (4.6L) engines rated 175-300 HP
• All components engineered to OEM specifications for reliable performance

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.

Technical Specifications

Package Contents

This service kit includes the following components:

• 8M0123025 Oil Filter × 1 View Part →
• 8M0106635 Fuel Filter × 1 View Part →
• 830749.0 Lower Unit Drain Gasket × 6
• 24OP149 Gear Oil Pump × 1
• 830749 Lower Unit Drain Gasket × 6

Installation Guide

1. Preparation: Ensure the engine is off and cooled down completely. Gather necessary tools including wrenches, a drain pan, and clean rags.
2. Oil Filter Replacement: Locate the oil filter on your engine block. Using an appropriate filter wrench, remove the old oil filter and replace it with the new 8M0123025 filter, hand-tightening securely.
3. Fuel Filter Replacement: Locate the fuel filter assembly in the fuel line. Disconnect fuel lines carefully, replace the old fuel filter with the new 8M0106635 filter, and reconnect all fuel line connections securely.
4. Lower Unit Service: Position the engine vertically and place a drain pan beneath the lower unit. Remove the drain and vent plugs to allow old gear oil to drain completely.
5. Gasket Replacement: Clean the drain and vent plug surfaces thoroughly. Install new 830749 lower unit drain gaskets on both drain and vent plugs to ensure a proper seal.
6. Refill Gear Oil: Using the included 24OP149 gear oil pump, insert the pump nozzle into the lower drain hole. Pump fresh gear oil until it reaches the upper vent hole.
7. Secure Plugs: Quickly install the vent plug with a new gasket while oil is still flowing, then install the drain plug with a new gasket. Tighten both plugs to manufacturer specifications.
8. Final Inspection: Wipe down all serviced areas and check for leaks. Start the engine briefly and inspect all filter and plug locations for proper sealing.

Troubleshooting & FAQ

Q: How do I confirm this service kit fits my Mercury engine?
A: This kit is designed for Mercury V6 (3.4L) and V8 (4.6L) engines rated between 175-300 HP. Verify your engine displacement and horsepower rating on your engine's identification plate or consult your owner's manual. You can also use the Mercury serial number guide linked above to confirm compatibility.

Q: How often should I perform this service on my Mercury outboard?
A: Mercury recommends changing the oil and fuel filters every 100 hours of operation or annually, whichever comes first. Lower unit gear oil should be changed every 100 hours or seasonally, especially before winter storage, to prevent moisture accumulation and gear damage.

Q: Can I reuse the lower unit drain gaskets if they look undamaged?
A: No, always replace drain gaskets during service even if they appear intact. Old gaskets compress and lose their sealing ability, which can lead to gear oil leaks and potential lower unit damage. This kit includes 12 gaskets to ensure you have fresh seals for multiple services.

Q: What type of gear oil should I use with the included pump?
A: Use Mercury Premium or High Performance gear lube as specified in your owner's manual. The included gear oil pump (24OP149) is designed to work with standard gear oil viscosities and makes the filling process clean and efficient.

Q: What are signs that my filters need immediate replacement?
A: Common symptoms include reduced engine performance, difficulty starting, rough idling, decreased fuel efficiency, or visible contamination in old filters. If you notice any of these issues between regular service intervals, inspect and replace filters as needed.

Q: Is this an OEM or aftermarket part?
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.