The Mercury OEM 40 AMP stator remains the standard ignition and charging component for a wide range of V6 2-stroke outboards produced from the late 1980s through the 1990s. Found in many of Mercury's most popular performance engines, the 40 AMP stator is responsible for both ignition signal generation and high-output charging in dual-regulator electrical systems.
Designed to work in tandem with Mercury’s dual voltage regulators, this stator supports critical electrical loads while delivering the voltage needed to power ignition coils and onboard electronics. Its robust output capability ensures clean spark and steady battery charging, even during extended high-RPM operation.
Original Equipment Design and Output
Mercury’s 40 AMP stator is built around a fixed-coil alternator design and uses internal windings to create both low-voltage ignition pulses and high-voltage AC power, which is regulated and rectified to supply DC-current to the boat’s battery and electrical system. The OEM stator is mounted beneath the flywheel, which can be removed using the Flywheel remove tool found on this website.
The factory stator is capable of producing up to 40 amps of charging output under full load, providing sufficient current for dual-battery setups, livewell pumps, gauges, trim systems, and marine electronics. It also feeds voltage to the ignition switch boxes. Maintaining stable output from the stator is critical for smooth engine performance, especially at idle and during high-RPM throttle transitions.
Mercury OEM Part Numbers and System Type
The Mercury 40 AMP stator is most commonly found under OEM part number 398-9610A19 and its earlier version 9610A19. This stator is designed specifically for dual-regulator configurations and is not compatible with earlier systems using a single, water-cooled regulator.
Its physical design includes dual yellow AC leads for regulator input, as well as ignition-related trigger wires when used in conventional switch box setups. This factory part is known for its dimensional consistency and drop-in compatibility with Mercury V6 outboards that use the high-output dual-regulator system.
Engine Model Compatibility and Fitment Range
The Mercury OEM 40 AMP stator fits a wide range of 2-stroke V6 models produced between 1989 and 1999, covering 2.0L, later 2.4-Liter, and 2.5L outboards. Among the most common applications are the 150 HP 2.0L, XR6, 175 HP, 200 HP, 200 HP EFI, and 225 HP Pro Max outboards. These engines are typically found on bass boats, offshore fishing rigs, and performance hulls that demand high electrical output for accessories and electronics.
Other supported configurations include the 150 XR2, 200 XRi, 175 HP EFI, and 2.5L 225 EFI models that use dual external voltage regulators and the 40 AMP stator as part of their ignition and charging circuit. Engines equipped with Mercury’s Pro Max and Super Magnum trim often rely on this stator to maintain consistent ignition performance during full-throttle operation.
This stator is used in both carbureted and early EFI Mercury V6 outboards, and its broad compatibility ensures consistent output across various cylinder counts and displacement classes.
Performance and Maintenance Considerations
The Mercury OEM stator delivers factory-rated performance and is trusted for its durability under normal marine conditions. However, over time, stators may degrade due to heat, vibration, and corrosion—leading to symptoms such as weak spark, intermittent ignition, or undercharging at higher RPM.
Routine inspection of stator leads and ground integrity is critical for long-term operation. Early signs of failure often include melted wire insulation, cracked potting compound, or voltage drop across output wires. In many cases, stator-related issues manifest as regulator failures, since a weakened or spiking stator can overload the voltage regulator circuit.
Using a genuine Mercury OEM stator ensures proper coil resistance, winding count, and thermal performance. Factory units are built to withstand sustained engine bay temperatures and long-duration operation without loss of output, maintaining compatibility with Mercury’s CDI switch boxes and ignition timing curves.
The Mercury OEM 40 AMP stator, part number 398-9610A19, remains the proven electrical backbone for 2.0L, 2.4L, and 2.5L Mercury V6 outboards built from 1989 through 1999. It supports high-current charging needs, delivers stable ignition voltage, and integrates seamlessly into dual-regulator marine electrical systems.
Trusted across engines like the 150 XR6, 175 EFI, 200 HP, Pro Max, and 225 EFI, this stator is essential for performance and reliability in factory and modified outboard applications.
Contact Mike Hill at mike@buckshotracing77.com or +1-714-697-1716 for tech support