The 40–60 4 CYL EFI FOURSTROKE CT SERV KIT-300 HRS is a complete, factory-approved service kit designed for Mercury 4-cylinder EFI FourStroke Command Thrust (CT) outboards in the 40HP to 60HP range. Specifically built for the 300-hour maintenance interval, this kit provides all the key components needed to keep your outboard engine running reliably, efficiently, and in peak condition.
This maintenance kit is tailored to suit the high demands of marine environments and supports optimal engine health. Included are a genuine Mercury water pump impeller and housing, oil filter, fuel filter, thermostat, spark plugs, and a full set of seals, gaskets, and drain screw washers. Every item in the kit is an OEM Mercury component—tested and engineered to factory standards to ensure long-lasting performance and perfect fitment.
One of the most critical components is the impeller, which is responsible for circulating cooling water through the engine. At 300 hours, impellers can show signs of fatigue or wear, reducing water flow and increasing the risk of overheating. Replacing this part proactively prevents potential damage and supports the cooling system’s performance.
The included thermostat ensures your engine maintains the correct operating temperature, which is essential for both performance and efficiency. Meanwhile, the oil and fuel filters work to capture harmful debris, ensuring clean lubrication and combustion. Clean spark plugs help deliver smooth starting, better throttle response, and reliable ignition.
The kit is designed to take the hassle out of routine maintenance. By bundling every essential part into one kit, it eliminates the need to source individual components—saving you time and giving you confidence that nothing will be overlooked. Whether you’re performing the service yourself or handing it off to a marine technician, this kit ensures all required parts are on hand.
Routine 300-hour servicing extends the life of your engine, improves fuel economy, and protects against avoidable failures. Especially in saltwater or heavy-use environments, sticking to the recommended service schedule is crucial. This kit provides everything you need to meet Mercury’s maintenance guidelines while keeping your outboard in top working order.
Trust the 40–60 4 CYL EFI FOURSTROKE CT SERV KIT-300 HRS to deliver factory-level reliability and all-in-one convenience, ensuring your time on the water is smooth, safe, and uninterrupted.