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Description
Champion RJ12YC Spark Plug #14 | Copper Core Nickel Resistor Plug
The Champion RJ12YC Spark Plug #14 is a conventional resistor spark plug designed for dependable ignition in compatible small engines, lawn mowers, outdoor power equipment, and other engine applications. Its copper-core center electrode provides excellent electrical conductivity and heat control, while durable nickel-alloy electrodes help provide consistent ignition performance and dependable service life.
Champion Part Number: 14
Spark Plug Number: RJ12YC
Features That Make a Difference
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Genuine Champion RJ12YC Spark Plug
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Champion Stock / Part Number: 14
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Conventional copper-core spark plug
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Nickel-alloy center and ground electrodes
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14 mm thread diameter
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1.25 mm thread pitch
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3/8" / 9.5 mm reach
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13/16" / 21 mm hex
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Gasket-style seat
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Solid terminal
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Extended-projection center electrode
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Built-in resistor helps reduce electrical interference
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Champion Heat Range 12
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Factory gap: 0.035" / 0.9 mm
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Suitable for compatible lawn, garden, small-engine, and outdoor power equipment applications
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Sold individually
Specifications
| Specification | Details |
|---|---|
| Champion Part Number | 14 |
| Spark Plug Number | RJ12YC |
| Product Type | Resistor Spark Plug |
| Brand | Champion |
| Thread Diameter | 14 mm / 9/16" |
| Thread Pitch | 1.25 mm / 1/16" |
| Reach | 9.5 mm / 3/8" |
| Hex Size | 21 mm / 13/16" |
| Seat Type | Gasket |
| Terminal Type | Solid |
| Preset Gap | 0.035" / 0.9 mm |
| Center Electrode Material | Nickel |
| Center Electrode Size | 2.5 mm / 3/32" |
| Center Electrode Projection | Extended Projection |
| Ground Electrode Material | Nickel |
| Ground Electrode Quantity | 1 |
| Resistor | Yes |
| Resistor Type | SAC9 |
| Heat Range | 12 |
Copper-Core Center Electrode
The Champion RJ12YC features a copper-core center electrode designed to provide efficient heat transfer and electrical conductivity.
The copper core helps control operating temperature while supporting consistent spark performance throughout normal engine operation.
Benefits include:
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Reliable ignition
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Efficient electrical conductivity
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Improved heat control
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Consistent engine starting
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Dependable combustion performance
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Good overall electrode durability
Nickel-Alloy Electrode Construction
The RJ12YC uses conventional nickel-alloy center and ground electrodes for dependable everyday performance.
The standard single-ground-electrode configuration provides a proven design suitable for compatible small engines and equipment requiring the RJ12YC specification.
Built-In Resistor
The RJ12YC is a resistor-type spark plug using Champion's SAC9 resistor design.
The resistor helps suppress radio-frequency and electromagnetic interference that can affect sensitive electrical components.
This is especially useful on equipment incorporating modern ignition systems and other electrical components.
Extended-Projection Design
The center electrode uses an extended-projection configuration, positioning the firing tip according to the engine design for which the RJ12YC is specified.
Correct spark plug reach and projection are important because using a plug with the wrong dimensions can affect combustion performance or potentially damage the engine.
Always use the spark plug specified by the engine or equipment manufacturer.
Designed for Lawn & Outdoor Power Equipment
The Champion RJ12YC is used on select engines found in applications such as:
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Zero-turn mowers
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Riding lawn mowers
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Lawn tractors
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Commercial mowers
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Small engines
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Lawn and garden equipment
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Outdoor power equipment
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Other compatible gasoline-engine applications
RJ12YC applications can include select engines used by major outdoor-power-equipment manufacturers.
Compatibility must be confirmed using the engine manufacturer's spark plug specification, equipment model, and engine model before ordering.
Spark Plug Gap
The Champion RJ12YC has a published gap of:
0.035" / 0.9 mm
However, the required installed spark plug gap can vary depending on the specific engine application.
Some equipment manufacturers may specify a different gap for the same RJ12YC spark plug.
Always check your engine owner's manual and adjust the plug gap to the equipment manufacturer's specification before installation.
Torque Specifications
Champion lists the following general installation torque ranges:
Cast-Iron Cylinder Head
26–30 lb-ft
Aluminum Cylinder Head
18–22 lb-ft
Actual torque requirements can vary by engine manufacturer.
Always follow the engine manufacturer's spark plug torque specification when available.
When to Replace Your Spark Plug
A Champion RJ12YC spark plug may need replacement when the existing plug has become:
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Worn
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Fouled
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Carbon-covered
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Oil-fouled
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Corroded
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Damaged
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Difficult to gap correctly
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Responsible for weak or inconsistent ignition
Common symptoms associated with a worn spark plug can include:
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Difficult starting
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Rough engine operation
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Misfiring
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Reduced engine performance
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Inconsistent idle
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Increased fuel consumption
Spark plug condition can also provide useful information about engine combustion and maintenance needs.
Installation & Maintenance
Before installing the spark plug:
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Turn off the engine and allow it to cool completely.
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Disconnect the spark plug wire.
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Clean dirt and debris from around the spark plug area.
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Remove the existing spark plug using the proper socket.
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Compare the old plug with the Champion RJ12YC.
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Confirm the required spark plug gap for your specific engine.
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Adjust the gap if required by the equipment manufacturer.
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Carefully thread the new spark plug into the cylinder head by hand.
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Tighten according to the engine manufacturer's torque specification.
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Reconnect the spark plug wire securely.
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Start the engine and verify proper operation.
Do not overtighten the spark plug. Incorrect plug reach, gap, or installation torque can cause engine damage.
Important Product Information
Champion Part Number: 14
Spark Plug: RJ12YC
Brand: Champion
Product Type: Conventional Resistor Spark Plug
Thread: 14 mm x 1.25 mm
Reach: 3/8" / 9.5 mm
Hex: 13/16" / 21 mm
Seat: Gasket
Preset Gap: 0.035" / 0.9 mm
Heat Range: 12
Resistor: Yes – SAC9
Electrode Material: Nickel Alloy
Center Electrode: Copper Core
Quantity: 1 Spark Plug
The Champion RJ12YC #14 Spark Plug combines a copper-core center electrode, nickel-alloy construction, resistor technology, and proven Champion design for reliable ignition in compatible engines and outdoor power equipment.
Why Buy from Barry’s Power Equipment?
Barry’s Power Equipment provides quality OEM and aftermarket maintenance parts for commercial lawn, landscaping, and outdoor power equipment.
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Champion spark plugs
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Small-engine maintenance parts
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Commercial mower replacement parts
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Ignition and tune-up components
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Competitive Pricing
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Fast Shipping
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Expert Customer Support
Keep your compatible engine starting and running properly with the Champion RJ12YC #14 Copper-Core Resistor Spark Plug.
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