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Mercury | 300 Hour Service Kit | 8/9.9 HP Command Thrust / Bigfoot | 8M0120867

Keep your Mercury 8HP or 9.9HP Command Thrust (Bigfoot) outboard running strong with this complete 300 Hour Service Kit – 8M0120867. Designed for engines with serial numbers 0R042475 and above, this kit includes the core maintenance components required at the 300-hour service interval to support performance, reliability, and long engine life.

At 300 hours, your outboard benefits from fresh lubrication, cooling system inspection, ignition refresh, and updated sealing components. This kit bundles everything together so you can complete the service efficiently without tracking down individual parts.

What’s Included in This Kit

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

Why the 300 Hour Service Matters

• Lubrication refresh: Replacing engine oil and gear lube helps maintain proper internal protection.
• Cooling system maintenance: A new thermostat and impeller kit support consistent operating temperature.
• Ignition reliability: Fresh spark plugs help ensure clean starts and efficient combustion.
• Corrosion protection: Replacing the anode helps defend internal components from galvanic corrosion.
• Leak prevention: New drain seals support proper sealing after service.

Fitment

• Mercury 8 HP Command Thrust (Bigfoot)
• Mercury 9.9 HP Command Thrust (Bigfoot)
• Serial Numbers 0R042475 & Above

This kit is engineered specifically for Bigfoot / Command Thrust gearcases. Always verify your serial number before ordering to ensure correct fitment.

• Engine Application
  • 9.9 HP Carb (209cc) - 0R042475-1R279944
  • 8 HP Carb (209cc) - 0R042475-1R279944