The Hobbywing SeaKing 2040SL V2 4000KV delivers sensorless brushless power for electric RC boats. Its water-cooling jacket helps carry heat away during demanding runs, while the black CNC-machined aluminium housing provides a durable motor assembly.

Features

• 4000KV winding for 2–3S LiPo operation
• 2-pole sensorless brushless design
• Water-cooling jacket with circulation channels and external cooling fins
• High-temperature windings and precision bearings
• 3mm output shaft

What’s Included

One SeaKing 2040SL V2 4000KV motor with water-cooling jacket and motor leads.

Compatibility

Hobbywing recommends this motor for RC boats up to 45cm long and pairs it with the SeaKing 30A V4 ESC. Use a 3mm motor-shaft coupling and a marine brushless ESC supporting the chosen battery voltage. The 2–3S motor rating applies alongside the ESC’s own voltage limit.

Installation

With the battery disconnected, secure the motor to its mount and align the shaft coupling. The mounting pattern is 4 × M2.5, with 3.5mm-deep holes; account for the mount thickness when selecting screw length. Connect the three motor leads to the ESC and secure the water-cooling hoses with clamps or ties. To reverse rotation, disconnect power and swap any two motor wires, or use the ESC’s motor-direction setting. Confirm cooling-water flow during operation.

What battery range does this version support?

The 4000KV 2040SL V2 is rated for 2–3S LiPo. The chosen battery must also be within the ESC’s voltage rating.

Is the water-cooling jacket included?

Yes. The motor comes with its water-cooling jacket, ready to connect to the boat’s cooling circuit.

Does it need a sensor cable?

No. This is a sensorless motor and connects to the ESC through its three motor leads.

What size shaft coupling does it use?

The motor output shaft is 3mm in diameter. Use a coupling with a matching motor-side bore.

Is an ESC included?

This listing is for the motor. The ESC, battery and boat installation hardware are separate.