Mercury 115HP

The Mercury 115 HP outboard is a four-stroke gasoline engine with multi-port electronic fuel injection (EFI), designed for reliable power, smooth acceleration, and efficient operation on a wide range of boats.

It runs on unleaded gasoline with a minimum octane rating of 87 (R+M/2) or 90 RON, and up to 10% ethanol is generally acceptable.

The Mercury 115 produces 115 horsepower, with peak performance typically between 5000–6000 rpm at full throttle.

It’s an inline-4 engine with an 8-valve SOHC design and about 2.1 liters of displacement, which delivers balanced torque and smooth performance.

Yes — it features Smart Start electric starting, making it easy to start in most conditions.

Yes — this engine supports Mercury SmartCraft digital technology, letting you display real-time engine data on compatible gauges and displays.

Typically available shaft lengths include 20″ (508 mm) and 25″ (635 mm), so you can choose based on your boat’s transom height and hull design.

Yes — most configurations come with power trim and tilt, which makes adjusting motor angle easier for performance and fuel efficiency.

Yes — some models offer a Command Thrust (CT) gearcase, which helps turn larger props and improves low-speed thrust for heavier boats without reducing top speed.

Dry weight varies by configuration but is typically around 359–363 lb (163–165 kg) depending on options.

Yes — thanks to the EFI system and advanced combustion design, the Mercury 115 delivers good fuel economy for cruising, fishing, and general boating.

It’s well-suited for small to medium planing hulls, like aluminum fishing boats, center consoles, inflatables, runabouts, and pontoons — where balanced performance and efficiency are desired.

Engine oil and filter change every ~100 hours or annually Lower unit gear oil replacement Fuel filter changes Water pump/impeller inspections Service frequency helps keep the engine reliable and efficient.

Yes — the 115 HP FourStroke is suitable for saltwater use, but you should flush it with fresh water after saltwater outings and follow good corrosion-control practices.

When properly maintained, Mercury FourStroke engines are known to be durable and long-lived. Proper fuel quality, regular service, and freshwater flushes extend engine life.

Yes — many owners perform basic tasks like oil changes and filter checks, but more complex diagnostics and internal work are best done by authorized Mercury technicians. Professional service helps maintain performance and protect your investment.