The Honda 31204-ZG4-802 Magnet Switch Assembly is a genuine OEM component designed for GCV520, GCV530, GXV520, GXV530, GX640, and GD320 engines, as well as H4518 and H5518 tractors. As a direct Honda OEM replacement, this assembly is built to the exact specification of the original part, ensuring correct operation in the starting circuit. Confirm your machine's serial number against the fitment table before ordering, as Honda supersedes parts at production breaks and this assembly covers a wide range of models.
Key Features
- Genuine OEM Switching Accuracy — sourced directly from Honda, this assembly delivers the correct magnetic pull force and contact engagement required for proper starter motor activation across all covered models.
- Direct OEM Replacement — designed as a drop-in replacement for the original unit, this part connects to existing wiring and mounting points without modification.
- Broad Fitment — covers GCV520, GCV530, GXV520, and GXV530 vertical shaft engines, the GX640 horizontal shaft engine, the GD320 horizontal shaft diesel engine, and H4518 and H5518 tractors.
- Serial Number Verification Recommended — Honda updates components at production serial breaks, so checking your unit's serial number against the fitment table ensures you receive the correct assembly for your build.
- Restored Starting Performance — a faulty magnet switch assembly can prevent the starter motor from engaging or cause intermittent no-start conditions; replacing it with this genuine part restores normal cranking and start-up behavior.
A magnet switch assembly — commonly called a starter solenoid — is an electromagnetically operated relay that sits between the battery and the starter motor. When the operator turns the ignition key or engages the start circuit, low-amperage current energizes the switch's coil, pulling a plunger that closes a set of heavy-duty contacts and sends high-amperage current to the starter motor to crank the engine. Because this component carries the full load of the starter circuit, a worn or failed switch can result in a clicking noise with no crank, sluggish starting, or a completely dead start circuit — symptoms that are often misdiagnosed as a battery or starter motor problem. Replacing the assembly with part number 31204-ZG4-802 restores the integrity of the start circuit and gets the engine turning over as designed.
Part Details
| Part Number | 31204-ZG4-802 |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Magnet Switch Assembly |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Horizontal Shaft Diesel Engine | GD320 | All |
| Horizontal Shaft Engine | GX640 | 1016334-9999999 |
| Lawn Tractor | H4518 | All |
| Multi-Purpose Tractor | H5518 | 1016334-9999999 |
| Vertical Shaft Engine | GCV520 | 1010780-9999999 |
| Vertical Shaft Engine | GCV530, GXV520, GXV530 | All |
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.
