The Mercury OEM 6-Pin Stator 821935A5 is an important electrical component used on select Mercury and Mariner 3.0 Liter V6 two-stroke outboards from the mid-to-late 1990s through approximately 2000.
 
Commonly searched as 821935A5, Mercury 3.0L stator, Mercury 225 stator, Mercury 250XB stator, and CDI 1935K2, this stator supports the engine’s ignition and electrical output system on compatible 3.0L carbureted and EFI V6 models.
 
This stator is commonly associated with 1995–2000 Mercury 225 HP Carb, 225 HP EFI, 225 Marathon 3.0L, 225 SeaPro 3.0L, 250 HP 3.0L, 250XB 3.0L, 300 Pro Max, and 300 Super Magnum outboards using the matching 6-pin stator configuration. Because Mercury used multiple ignition and charging layouts across the 3.0L platform, fitment should always be confirmed by serial number, original stator plug, and factory parts diagram.
 
What the Stator Does
 
On a Mercury 3.0L V6 two-stroke, the stator mounts beneath the flywheel and produces AC voltage as the flywheel magnets rotate around it. That electrical output is used by the engine’s ignition and charging system depending on the specific model configuration.
 
A healthy stator is critical for reliable starting, stable spark output, battery charging, and consistent engine performance through the RPM range.
 
As the stator ages, heat, vibration, deteriorated insulation, weak windings, or damaged wiring can reduce output. A failing stator may still allow the engine to start but create ignition breakdown under load, intermittent spark loss, weak charging, or poor high-RPM performance.
 
Common Symptoms of a Weak Mercury 3.0L Stator
 
A failing Mercury 821935A5 stator can cause hard starting, no spark, weak spark, rough idle, intermittent misfire, loss of RPM, poor acceleration, or an engine that runs correctly cold but fails after warming up. Some stator failures appear only under load, which is why an engine may sound fine on the hose but break down on the water.
 
Charging-related symptoms may include low battery voltage, an erratic tachometer, overheated regulator connections, or repeated regulator/rectifier failures. Because stator output feeds critical electrical circuits, diagnosis should include DVA testing, visual inspection, and verification of the regulator, rectifier, grounds, battery cables, and switch box connections.
 
Mercury 3.0L Fitment and Applications
 
This 6-pin stator is used on select Mercury and Mariner 3.0 Liter V6 two-stroke outboards, including many 225 HP, 250 HP, and 300 HP performance and workhorse models.
 
Common applications include 225 Carb 3.0L, 225 EFI 3.0L, 225 Marathon 3.0L, 225 SeaPro 3.0L, 250 3.0L, 250XB 3.0L, 300 Pro Max, and 300 Super Magnum engines. These motors were popular on offshore boats, bass boats, performance lake boats, commercial hulls, and high-horsepower Mercury Racing-style builds where reliable ignition output is essential.
 
This stator is not a universal Mercury V6 stator. It should not be confused with 2.0L, 2.4L, or 2.5L V6 stators, Optimax DFI stators, Verado components, or later SmartCraft-era charging systems.
 
Part Number Cross References
 
The primary OEM part number is Mercury 821935A5. The common CDI Electronics cross-reference is 1935K2. Strong SEO and parts lookup phrases include Mercury 821935A5 stator, Mercury 3.0L 6-pin stator, Mercury 225 EFI stator, Mercury 250XB stator, Mercury 300 Pro Max stator, and Mercury 300 Super Magnum stator.
 
Installation and Diagnostic Notes
 
Replacing a stator requires flywheel removal and should be done with the correct puller, proper service manual, and safe flywheel handling practices.
 
Before installing the replacement stator, inspect the flywheel magnets, stator mounting screws, wiring grommets, switch boxes, regulator/rectifier connections, battery cables, and engine grounds.
 
After installation, DVA output should be checked according to Mercury service specifications. Ignition and charging problems are often misdiagnosed when poor grounds, melted regulator wiring, weak batteries, or damaged harness connections are overlooked.
 
Buckshot Racing #77 Tech Tip
 
If a Mercury 3.0L V6 repeatedly burns regulators, drops spark at higher RPM, or loses charging output, do not replace parts blindly. Inspect the entire electrical system as a group.
 
A weak stator can damage other components, but poor regulator wiring, overheated connectors, or bad grounds can also destroy a good stator.
 
For Mercury 225 EFI, 225 SeaPro, 250XB, 300 Pro Max, and 300 Super Magnum owners, the 821935A5 6-pin stator is a key part of keeping the engine reliable. Correct diagnosis, clean wiring, and proper installation are just as important as the replacement stator itself.