The Honda 31750-Z0A-821 Regulator Rectifier Assembly is a genuine OEM component designed for GCV520, GCV530, and GXV390 vertical shaft engines. As an authentic Honda part, it meets the same specifications as the original unit it replaces, ensuring the charging system performs exactly as the engine was engineered to deliver. This assembly is the correct replacement when the original unit has failed or is showing signs of electrical issues, and confirming part number 31750-Z0A-821 against your engine's serial number before ordering will verify you have the right fit for your specific production run.
Key Features
- Correct Voltage Regulation and Rectification — as a genuine OEM assembly, this part handles both AC-to-DC conversion and voltage regulation in a single unit, maintaining the precise output levels Honda specifies for these engines
- Direct OEM Replacement — engineered to match the original component exactly, this assembly installs without modification on GCV520, GCV530, and GXV390 vertical shaft engines
- Charging System Integrity — a failed regulator rectifier causes erratic charging, battery drain, or complete loss of electrical output; replacing it with this genuine part restores consistent power delivery to the engine's electrical system
- Check Your Serial Number — Honda supersedes parts at production breaks, so verify your engine's serial number against the fitment table to confirm this assembly is correct for your unit
The regulator rectifier assembly serves two functions in the engine's charging circuit. The rectifier side converts the alternating current produced by the engine's charging coil into direct current usable by the battery and electrical accessories. The regulator side controls the output voltage, preventing overcharging that would damage the battery or connected components. When this assembly degrades, the symptoms range from a battery that will not hold a charge to voltage spikes that can harm other electrical parts — making prompt replacement with the correct genuine part essential to keeping the engine's electrical system operating as designed.
Part Details
| Part Number | 31750-Z0A-821 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Regulator Rectifier Assembly |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Vertical Shaft Engine | GCV520, GCV530 | 1005448-9999999 |
| Vertical Shaft Engine | GXV390 | 1033849-9999999 |
Verify Before You Order
Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.
Why Buy From DHS Equipment
Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.
Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.
