8M0149930 Maintenance Kit for Mercury V6 V8 | JLM Marine
This comprehensive maintenance kit is engineered for Mercury V6 3.4L (200-350 HP) and V8 4.6L outboard engines, including CMS SeaPro & ProXS models as well as V8 4.6L 250-300hp AMS Sea-Pro and Racing applications. It provides all essential service components for thorough preventive maintenance in a single package.
Direct replacement for OEM part number 8M0149930, this kit consolidates critical wear items—impellers, seals, gaskets, filters, and thermostat—to streamline your service routine and ensure reliable engine performance.
- Includes impeller, thermostat, fuel filter, oil filter, and all necessary seals and gaskets
- Complete service solution for V6 and V8 Mercury outboards
- Gear oil pump included for convenient fluid changes
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Mercury |
8M0149930 |
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.
| Brand |
Model |
Rated HP |
Notes |
| Mercury |
V6 3.4L |
200-350 HP |
CMS SeaPro & ProXS |
| Mercury |
V8 4.6L |
250-300 HP |
AMS Sea-Pro and Racing |
Technical Specifications
| Specification |
Value |
| OEM Part Number |
8M0149930 |
| Application |
V6 3.4L 200-350 HP; V8 4.6L 250-300 HP |
| Kit Type |
Comprehensive Maintenance Kit |
Package Contents
This maintenance kit includes the following components:
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47-43026Q02 (Impeller) × 1
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26-8M2014338 (Seal) × 1
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2210 (Seal) × 1
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8172761 (Plate) × 1
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25-21836 (O-ring) × 2
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27-8M0142616 (Plate) × 1
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27-8172771 (Gasket) × 1
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28-8M0032833 (Key) × 1
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27-8M46938 (Gasket) × 1
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25-8M0142659 (Seal) × 2
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26-830749 (Seal Formed) × 2
- 8M0162139 (Thermostat) × 1
- 35-8M0106635 (Fuel Filter) × 1
- 35-8M0123025 (Oil Filter) × 1
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8M007119 (Drain Gasket) × 1
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830749 (Drain Gasket) × 3
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24OP149 (Gear Oil Pump) × 1
Installation Guide
- Disconnect the battery and ensure the engine is cool before beginning maintenance work.
- Remove the lower unit according to your engine's service manual to access the water pump housing.
- Disassemble the water pump housing and remove the old impeller. Inspect the housing for wear or corrosion.
- Install the new impeller (47-43026Q02) with a light coating of marine grease on the blades, ensuring proper rotation direction.
- Replace the water pump plate (8172761) and install new gaskets (27-8172771, 27-8M46938) and seals as indicated in the kit.
- Install new O-rings (25-21836) and seals (25-8M0142659, 26-830749, 26-8M2014338, 2210) in their designated locations.
- Replace the thermostat (8M0162139) in the cooling system housing, ensuring proper orientation and seal placement.
- Change the engine oil and replace the oil filter (35-8M0123025) with a new drain gasket (8M007119).
- Replace the fuel filter (35-8M0106635) according to manufacturer specifications, checking fuel lines for cracks or leaks.
- Use the gear oil pump (24OP149) to drain old lower unit oil and refill with fresh marine gear oil until it flows from the upper vent hole. Install drain gaskets (830749) on both drain and fill plugs.
- Reassemble the lower unit to the engine, torquing all fasteners to specification and ensuring proper alignment.
- Reconnect the battery, start the engine, and verify strong water flow from the telltale outlet and proper operating temperature.
Troubleshooting & FAQ
Q: How do I confirm this kit fits my specific Mercury engine?
A: Cross-reference your engine model and horsepower with the compatibility table above. This kit is designed for Mercury V6 3.4L (200-350 HP) and V8 4.6L (250-300 HP) engines in CMS SeaPro, ProXS, AMS Sea-Pro, and Racing configurations. Verify your engine's serial number using the Mercury identification guide linked above.
Q: How often should I perform this maintenance service?
A: Mercury recommends annual maintenance or every 100-300 hours of operation, whichever comes first. If you operate in sandy, silty, or debris-heavy water, inspect the impeller and seals more frequently. Always follow your engine's service manual for specific intervals.
Q: What are the signs that my impeller or thermostat needs replacement?
A: Weak or no water flow from the telltale, engine overheating, or steam from the engine are primary indicators. Worn impeller blades, cracked seals, or a stuck thermostat can cause cooling system failure and serious engine damage if not addressed promptly.
Q: Can I install this kit myself or do I need a professional?
A: If you have mechanical experience and the proper tools, you can perform this service following your engine's manual. However, improper installation—especially of the impeller, seals, or thermostat—can lead to overheating and engine damage. Professional installation is recommended if you're unsure.
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?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.