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Mercury | 300 Hour Service Kit | 20/30 HP | 8M0120839

The Mercury 300 Hour Service Kit – 8M0120839 provides the key maintenance components required to service Mercury 20 HP and 30 HP four-stroke outboards with serial numbers 0R106999 and above. This complete kit packages the essential oils, filters, cooling system components, ignition parts, and seals required for the recommended 300-hour service interval.

Routine maintenance is critical for maintaining engine reliability, cooling performance, and proper lubrication. By replacing common wear items such as spark plugs, filters, thermostat components, and the water pump impeller, this service kit helps keep your Mercury outboard operating efficiently and reliably season after season.

What’s Included in This Kit

• 2 x Quarts 25W-40 Engine Oil
• 1 x Quart Gear Lube
• 1 x Oil Filter
• 1 x Fuel Filter
• 1 x Oil Drain Seal
• 2 x Gearcase Drain Seals
• 1 x Thermostat
• 1 x Thermostat Gasket
• 3 x Spark Plugs
• 1 x Water Pump Impeller Kit
• 1 x Anode

Benefits of the 300 Hour Service

• Maintain proper lubrication with fresh engine oil.
• Protect the gearcase with new gear lube and drain seals.
• Ensure cooling system efficiency with a new thermostat and impeller.
• Improve ignition performance with fresh spark plugs.
• Reduce corrosion by replacing the sacrificial anode.

Engine Compatibility

• Mercury 20 HP Four-Stroke Outboards
• Mercury 30 HP Four-Stroke Outboards
• Serial Numbers 0R106999 and Above

Always verify your Mercury outboard serial number before ordering to ensure proper compatibility.

• Engine Application
  • 25 HP EFI Jet 3 CYL - 0R165086-1R162636
  • 30 HP EFI 3 CYL - 0R106999-1R162636
  • 25 HP EFI 3 CYL - 0R106999-1R162636
  • 25 HP Carb SeaPro - 0R051710 and up