The Honda 98079-5547G Spark Plug (ZFR5F-4) is a genuine OEM ignition component designed for GX630, GX660, and GX690 horizontal shaft engines. As a direct Honda OEM part, this spark plug is the exact specification Honda engineers selected for these large-displacement commercial engines, ensuring the correct heat range and electrode gap for proper ignition. If your engine is misfiring, showing poor fuel economy, or refusing to start cleanly, replacing the spark plug with part number 98079-5547G is the logical first step. Always confirm your engine's serial number against the fitment table before ordering, as Honda may supersede parts at specific serial breaks.
Key Features
- Correct Heat Range and Electrode Spec — the ZFR5F-4 designation identifies a specific heat range and four-ground-electrode design engineered for the combustion demands of the GX630, GX660, and GX690 engines; a mismatched plug causes fouling or pre-ignition
- Genuine Honda OEM Part — sourced directly from Honda, this is the same spark plug Honda installs at the factory, so there is no guesswork about compatibility or specification
- Fits GX630, GX660, and GX690 Horizontal Shaft Engines — covers Honda's flagship large-displacement commercial horizontal shaft engine range; check your serial number against the fitment table to confirm your specific build
- Restores Clean Ignition — a worn or fouled plug causes hard starting, rough running, and increased fuel consumption; a fresh OEM plug restores the crisp spark timing these engines rely on for consistent power output
A spark plug is the final link in the ignition chain, creating the timed electrical spark that ignites the air-fuel mixture inside the combustion chamber. In large-displacement commercial engines like the GX630, GX660, and GX690, the heat range of the plug must be precisely matched to the engine's operating temperature — too cold and the plug fouls with carbon deposits, too hot and it risks pre-ignition damage. When a spark plug degrades, symptoms range from hard starting and rough idle to misfires under load; replacing it at the recommended service interval keeps combustion efficient and the engine running at full output.
Part Details
| Part Number | 98079-5547G |
|---|---|
| Brand | Honda |
| Part Type | Genuine OEM |
| Description | Spark Plug (ZFR5F-4) |
Compatibility & Fitment
| Name | Models | Serial Range |
|---|---|---|
| Horizontal Shaft Engine | GX630, GX660, GX690 | 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.
