The Multiquip 491055S Spark Plug (RC12YC) is a genuine OEM ignition component designed for HHNG5 series Whiteman ride-on power trowels. Sourced directly from Multiquip, this spark plug is the correct OEM specification for the engine fitted to the HHNG5, ensuring the right heat range, thread pitch, and electrode gap right out of the box. Keeping the correct spark plug installed is one of the simplest ways to protect engine performance and fuel efficiency on your trowel. DHS Equipment stocks the 491055S so you can get your machine back to work without hunting down compatibility information.
Key Features
- Correct Heat Range for This Engine: — The RC12YC designation specifies an exact heat range matched to the engine on the HHNG5 — not a generic cross-reference that may run too hot or too cold.
- Genuine OEM Component: — Supplied by Multiquip as an original equipment part, so electrode material, gap spec, and thread dimensions meet the original design intent for this application.
- Drop-In Installation: — Thread size, reach, and seat type match the OEM plug exactly, allowing straightforward installation without re-gapping or adapter hardware.
- HHNG5 Series Fitment Confirmed: — Verified fitment for Whiteman HHNG5 ride-on power trowels — cross-reference your model before ordering to confirm applicability.
- Engine Performance Protection: — A correctly specified spark plug sustains clean combustion, stable idle, and consistent throttle response; a worn or mismatched plug can cause hard starts, misfires, and increased fuel consumption on the trowel engine.
A spark plug ignites the air-fuel mixture inside the engine cylinder, initiating the combustion event that drives the power stroke. The RC12YC designation identifies a specific heat range, meaning the plug is engineered to transfer combustion heat away from the electrode at a rate matched to this engine's operating temperature. When a spark plug wears out or is replaced with an incorrect specification, the result is typically hard starting, rough idling, misfiring under load, or fouling — all of which reduce the productivity of the trowel and put additional strain on ignition components.
Have questions about fitment or need help confirming this is the right part for your machine? Contact the DHS Equipment parts team for assistance.
Part Details
| Part Number | 491055S |
|---|---|
| Brand | Multiquip |
| Part Type | Genuine OEM |
| Description | Spark Plug (RC12YC) |
Compatibility & Fitment
| Name | Model |
|---|---|
| Whiteman Ride-On Power Trowels | HHNG5 |
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.
