Mercury 6 HP Manual Start Long Shaft Outboard Engine

The Mercury FourStroke 6 ML is a 4-stroke outboard marine engine designed for small fiberglass, aluminum, or inflatable boats requiring a long shaft, measuring 2.5–5 meters, with a 6 HP / 4.5 kW and 123 cc 1-cylinder engine. The FourStroke 6 ML, with its 123 cc EFI FourStroke engine, offers economical and reliable power to small and medium-sized boat users.

FourStroke 6 ML Series Features and Technology Advantages

The 2-cylinder structure offers balanced power with a compact and lightweight design. EFI injection ensures reliable starting without requiring a manual fuel system.

• 1-Cylinder Engine (123 cc): The 2-cylinder structure offers balanced power with a compact and lightweight design
• Long Shaft (508 mm (20")): The propeller operates at optimal depth with the correct transom height
• EFI Electronic Injection: No primer bulb needed — automatic fuel system prime before turning the key
• Manual Start: Battery-independent reliable mechanical starting
• Manual Trim: Manual adjustment of transom angle — simple and reliable mechanical structure
• 1 Liter Integrated Tank: Compact structure that doesn't require an external tank — sufficient for short-distance use

Long Shaft — Which Boat Type Is It Suitable For?

The long shaft (508 mm (20")) is suitable for the vast majority of inflatable boat, aluminum, and fiberglass boat models. For boats with a transom height of 381 mm, a short shaft model should be preferred.

Technical Specifications

Who Is This Engine For?

• 2.5–5 meter small to medium-sized boat: economical EFI power
• Fishing and coastal use: quiet 4-stroke operation
• Inflatable boat and RIB: lightweight engine and balanced thrust
• Auxiliary engine: reliable Mercury service network access

Maintenance and Longevity

4-stroke Mercury engines operate trouble-free for many years with regular oil changes and a seasonal maintenance protocol. The impeller of the water-cooled system should be checked every 100 hours or every two seasons. In saltwater use, flushing with fresh water after each use is mandatory.

Related maintenance categories: Maintenance Kit | Engine Oil | Impeller | Mercury Spare Parts

Frequently Asked Questions

What boat size does the Mercury FourStroke 6 HP engine fit?

6 HP power can fit different sizes depending on boat weight and type. General rule: 15–20 kg boat weight per HP. Always check the maximum engine power recommended by the boat manufacturer.

What advantage does the EFI system offer over a carbureted engine?

EFI (Electronic Fuel Injection) does not require a primer bulb or choke adjustment. It provides reliable starting in cold weather and at high altitudes, consistent power output, and lower fuel consumption compared to carbureted alternatives.

What are the maintenance intervals for Mercury FourStroke?

Oil change at the first 20 hours, then oil change every 100 hours or once per season. Impeller check every two seasons. In saltwater use, flushing with fresh water after each use is mandatory. Fuel system protection at the end of the season is recommended.

Which boat and inflatable boat brands are compatible with the FourStroke 6 ML?

Mercury outboard engines are compatible with many fiberglass, aluminum, and inflatable boat models thanks to their universal transom clamp or transom mounting system. The only criteria are your boat's 508 mm (20") transom height and the maximum engine power approved by the manufacturer. You can get compatibility confirmation from Clever Marin by sharing your boat model.

Related Products and Categories

• Mercury Outboard Engines
• Mercury Marine Products
• Mercury Spare Parts
• Mercury 2.5–30 HP FourStroke
• Mercury 40–60 HP FourStroke
• Outboard Engines
• Boat Engines
• Maintenance Kit
• Impeller
• Anode

Is It the Right Configuration for Your Boat?

Share your boat model, transom height, and intended use — let's confirm together if the Mercury FourStroke 6 ML engine is suitable for your boat and the correct shaft selection.