Yamaha plans outboard engine with built-in electric trolling motor

The plans, revealed in a US Patent and Trademark Office document released yesterday, shows an outboard engine with an electrically powered prop mounted inside the drive leg.

In slightly different applications, the document also shows electric thrusters mounted on a bracket attached to the outboard engine, one bolted to the transom, and another mounted on the bow via a special bracket.

The concept works on the electric props being submerged in water while the boat is moving at low speeds, but sitting up out of the water while the boat is up on a plane. The propeller’s direction is changed via an electric motor mounted on top of the unit.

The electric motors are linked to a joystick controller mounted in the boat’s cockpit, drawings filed with the patent application reveal.

The bow-mounted thruster can either be fixed, or retractable, pulling back into the boat when not in use. Anglers fit electric trolling motors to the bow of a boat because pulling instead of pushing makes the craft much easier to control.

The bolt-on version of the electric thruster is believed to allow Yamaha to retrofit the devices for existing outboard engine owners.

The current generation of electric trolling motors are generally mounted on special plates fitted to the bow of fishing boats, and must have their direction and thrust set manually. Other versions have included devices that clip onto the outboard engine drive leg.

Yamaha’s larger engine range already has its Helm Master system for offshore boats, which uses a joystick to control the craft’s low-speed maneuvering. Optimised for twin-, triple- and quad-rigged boats using Yamaha outboards ranging in performance from 150hp-425hp, the system can also keep the bow pointed into current, drift in a set direction, and even hold the boat at station.

When docking, Helm Master is able to control multiple outboard engines to behave as though the boat was fitted with a bow thruster.

Yamaha's smaller outboard engine range also comes with a trolling function that allows the engine to idle as low as 650rpm, and up to 900rpm in 50rpm increments.

It potentially means the smaller electric thruster will be optimised for single-engine applications in smaller craft.