Electric Outboards on Leisure Yachts

Leisure 17 and Leisure 20

Currently the smaller Leisure yachts are most suited to the use of electric/battery propulsion with these recommendations

1 kW / 3 HP equivalent (e.g., ePropulsion Spirit 1.0 EVO, Torqeedo Travel 1103 C): 

Ideal for day-to-day motoring, calm water, and marina tight spots. Provides ~4–5 knots top speed.

3 kW / 6 HP equivalent (e.g., ePropulsion Navy 3.0, Torqeedo Cruise 3.0): 

Recommended if you regularly battle strong tidal currents, choppy open water, or head winds where extra thrust is needed to safely push the 800 kg displacement of the yacht.

Discussion on electric versus petrol on L17

Disadvantages of electric outboards:  

Limited High-Speed Range:

Drag increases rapidly on displacement hulls like the Leisure 17. Running an electric outboard at full throttle (e.g., trying to punch through strong tidal currents or heavy sea swells) will deplete the battery quickly, often within 45–60 minutes.  Making long passages is not really feasible.

High Upfront Cost:                                                    Complete setups—including the motor, high-capacity lithium battery, and specialized marine charger—are significantly more expensive than standard 4–6 HP 4-stroke petrol outboards.

Charging Infrastructure & Time: 

Recharging a marine lithium battery takes hours rather than minutes. If you are at a swing mooring or anchored away from shore power without a generator or substantial solar array, topping off a depleted battery is difficult.  

Transom Weight Distribution:   

Standard 1 kW units with integral transom-mounted batteries can make a small yacht tail-heavy. Upgrading to higher-power motors (such as 3 kW units) requires external battery banks, which consume valuable locker space inside a compact 17-foot cabin.

Handling Strong Tides & Headwinds:  

A 1 kW (~3 HP equivalent) motor may struggle to make ground against a strong ebb tide or adverse wind, whereas a 3 kW unit will do the job but demands a larger investment and heavy battery pack.

Disadvantages of Petrol Outboards:

Maintenance & Starting Reliability: 

Four-stroke petrol engines have intricate fuel systems, carburetor jets, spark plugs, and water pump impellers. Small outboard carburetors easily clog with degraded fuel or salt deposit buildup, making them prone to hard starting or stalling, especially after sitting idle for long periods.

Fuel Safety & Cabin Fumes: 

Petrol is volatile, and its vapors are heavier than air. On a small boat like an L17 with limited ventilation, petrol fumes can sink into the bilge or cabin, posing a fire and explosion hazard as well as an unpleasant smell throughout the interior.

Awkward Handling & Transom Weight:

Lifting a 4–6 HP petrol outboard on and off the stern bracket to stow it or service it requires significant effort. Four-stroke engines are heavy, and having that weight cantilevered far back on the transom can pull down the stern and affect the boat's trim when sailing.

Noise, Vibration & Exhaust: 

Petrol outboards generate significant mechanical noise, cockpit-rattling vibration, and smelly exhaust fumes that frequently blow back over the crew when motoring downwind or maneuvering in marinas.

Refuelling Can Be Messy: 

Refueling from portable fuel cans while bobbing on the water is awkward, risking petrol spills directly onto the deck, into the sea, or inside the cockpit lockers where the fuel tank is stowed.

Engine Tilting & Drag: 

When under sail, a petrol outboard must be tilted out of the water to eliminate hydrodynamic drag. Because of their weight and bulky power heads, pulling them up and locking them off on a transom bracket can be physically demanding on a small yacht.

Advantages of An Electric Outboard

Instant, Effortless Starting: 

There are no pull cords, chokes, or engine warm-up procedures. Starting requires only a button push or throttle twist, providing reliable propulsion when maneuvering in tight spots or when the wind drops.   

Silence & Zero Fumes: 

Electric motors operate virtually silently with no mechanical noise or exhaust fumes. This makes motoring much more pleasant inside the cockpit and cabin, allows easy communication without shouting.   

Low Maintenance & High Reliability: 

Electric outboards eliminate spark plugs, carburetors, impellers, and fuel lines. Because there is no fuel to degrade or clog small jets, the motor requires minimal seasonal servicing and remains dependable after long periods of storage.   

Cleaner & Safer Storage: 

Without petrol or engine oil onboard, there is no risk of fuel leaks, oily bilges, or explosive fumes lingering in the enclosed cabin of an L17.   

Modular Weight & Easy Handling: 

Modern integrated units (such as the ePropulsion Spirit or Torqeedo Travel) feature  removable, detachable batteries. Carrying the motor component and battery separately makes mounting and dismounting the outboard on the stern bracket far lighter and safer than lifting a heavy 4-stroke petrol engine.   

Instant Torque & Low-Speed Control: 

Electric motors deliver full torque instantly, providing immediate response and precise control when docking or maneuvering at low speeds.   

Hydrogeneration (On Select Models): 

Certain models (like the ePropulsion Spirit 1.0 EVO) can recharge their own batteries using the free-wheeling propeller while the boat is under sail, offering free off-grid power generation.

Advantages of a Petrol Outboard

While electric propulsion has gained popularity, traditional petrol outboards still offer key advantages for a Leisure 17.

Unrestricted Range & Rapid Refuelling: 

Petrol provides high energy density, allowing for extended motoring at cruising speeds without worrying about running out of battery power. Refuelling takes only minutes with a portable fuel container.  It is still the only option for making long passages or multi-day coastal trips.

Lower Upfront Cost: 

A standard 4-stroke petrol outboard (typically 4–6 HP) is significantly less expensive to purchase initially compared to a complete electric motor, lithium battery, and marine charger setup.

Superior Power for Strong Tides & Currents: 

A 5 HP or 6 HP petrol engine provides substantial thrust to punch through strong ebb tides, heavy sea swells, or harsh headwinds without depleting a limited battery capacity within an hour.

Independence from Shore Power: 

Petrol outboards do not require access to marina shore power, heavy solar setups, or generators to keep you moving, making them ideal for swing moorings, remote anchorages, or off-grid sailing.

Integrated Battery Charging: 

Many 4-stroke petrol outboards feature an integrated alternator (lighting coil) that can charge 12V onboard lead-acid or AGM batteries while the engine is running, supplying power for cabin lights, instruments, and navigation equipment.