Mercury F20 EFI 20HP – Compact Power & Efficiency for Small Boats

The Mercury F20 EFI is a 20HP four-stroke outboard that delivers big performance for small boats. It’s equipped with a 333cc inline 2-cylinder engine that is lightweight yet robust, giving the F20 an impressive power-to-weight ratio. With EFI (Electronic Fuel Injection), this outboard starts quickly and reliably with no choke and provides smooth, consistent throttle response. One standout feature of the F20 (and F15) is Mercury’s Adaptive Speed Control – a technology that automatically maintains engine RPM regardless of changes in load or conditions. This means when you’re trolling or navigating at low speeds, the F20 won’t bog down if, for example, you encounter a swell or make a sharp turn; it will adjust fuel and timing to keep a steady pace, resulting in better control and a more enjoyable driving experience.

Despite its strong performance, the F20 remains highly portable, weighing approximately 45 kg for manual-start models and around 47 kg for electric-start versions. This makes it practical for boats that need the motor taken on and off regularly, such as inflatable dinghies or small tenders. Installation and removal are further eased by the engine’s large carry handles and redesigned mounting clamp. The F20 can be ordered with either tiller steering or remote steering. The tiller handle has an ergonomic grip and allows both left- or right-handed operation, and it includes forward-neutral-reverse shifting, throttle and throttle friction adjuster, and stop switch right at your fingertips. For convenience on small boats, the engine also features an integrated 12A alternator to charge a battery or power small electronics – especially useful on the electric-start models (note: EFI on the F20 is battery-free, meaning even pull-start versions have EFI without needing a separate battery).

Mercury has built the F20 to be durable and user-friendly. The engine uses a through-prop exhaust to direct fumes underwater and reduce noise. Vibration is minimized through precision engine mounts and the inherently balanced design of the inline twin. Cooling is water-regulated by a thermostat for optimal operating temperature, and the F20 includes protections for low oil pressure and over-revving to safeguard the engine. Maintenance is straightforward: oil changes, spark plug checks, and fuel filter replacements are simple, with easily accessible service points. The F20 is a popular choice among fishermen and casual boaters alike – whether pushing a 3-4m aluminum fishing boat, a small RIB for diving, or serving as an auxiliary on a sailboat, this engine provides reliable 20HP power, quiet operation, and excellent fuel economy to keep your adventures going strong.

Use Cases & Recommendations:
– Ideal for small RIBs, inflatables, jon boats, and aluminum skiffs (3–4.5 m), providing ample power while keeping weight low for easy planing and handling
– Excels at trolling and slow cruising – Adaptive Speed Control keeps the speed steady, making it great for fishing where consistent trolling speed is key
– A top choice for sailboat tenders and portable applications, where its light weight and battery-free EFI starting mean less hassle when deploying or storing the engine
– Suitable as a primary engine for small utility or rescue boats, offering dependable starts and simple operation in critical moments
– Great for remote locations or rental fleets, given its robust construction, easy maintenance, and Mercury’s support network – ensuring it can take on frequent use and still perform reliably