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NGK 4015 Spark Plug
| Brand | NGK 4015 |
|---|---|
| Resistance | 5000 |
| Ground Electrode Tip Design | Standard |
| Ground Configuration | Standard |
| Ground Electrode Core Material | Nickel |
| Electrical Terminal Type | Non-removable nut |
| Center Electrode Core Material | Copper |
| Center Electrode Tip Material | Nickel |
| Pre-Gap Size | .024 |
| Ground Electrode Quantity | 1 |
| Hex Size | 13/16 |
| Insulator Height | 55.00 |
| Manufacturer Heat Range | 9 |
| Seat Type | Flat |
| Reach | .75 |
| Thread Diameter | 14.00 |
| Part Number | Br9eg solid |
| Stock Number | 4015 |
| Product line | Racing Spark Plug |
| Fits | Yamaha · 8 vehicles |
Copper core. Promotes stable ignition performance in demanding racing use.
Pre-gapped. Specified at 0.024 inch for the listed application.
Racing plug. Built for secondary ignition service in performance applications.
Cross-references CSF 4015 for the same application. See all 1.
Will it fit your vehicle?
Free return shipping if it doesn't fit.
Overview
NGK Racing Spark Plug 4015 is a performance ignition component built around a copper core center electrode, nickel tip materials, and a standard ground electrode design. It is specified with a 0.024-inch pre-gap and a 5000 resistance value for race kart applications.
Fits 1992-1993 Yamaha YZ125, N/A and fits 1999-2004 Yamaha YZ125, N/A. This NGK YZ125 spark plug is identified by part number 4015 and BR9EG SOLID.
Key Features
- Copper core center electrode for stable ignition performance.
- Nickel center and ground electrode tip materials.
- 0.024-inch pre-gap for the listed application.
- Standard ground configuration with a flat seat design.
- 14 mm thread diameter, 0.75-inch reach, and 13/16-inch hex size.
Detailed Description
NGK 4015, also listed as BR9EG SOLID, is a racing spark plug with a non-removable nut terminal and a manufacturer heat range of 9. The standard ground electrode layout and single ground electrode design support consistent spark delivery in demanding secondary ignition use. For buyers searching for a Yamaha YZ125 spark plug or NGK 4015 replacement, this part matches the listed race kart fitment and gap specification.
Common Uses
- Replacing a worn or fouled racing spark plug.
- Restoring consistent ignition in race kart use.
- Addressing misfire caused by incorrect plug gap.
- Replacing a plug with the wrong heat range or reach.
Installation Notes
Verify the thread diameter, reach, seat type, and pre-gap before installation. Confirm the application matches the listed Yamaha YZ125 fitment and use the specified 0.024-inch gap for the intended setup. Check the ignition system condition and cylinder head threads during service.
| Year | Make | Model | Liters | Cylinders | Notes |
|---|---|---|---|---|---|
| 2004 | Yamaha | YZ125 | -L | -- | Race Kart; Gap 0.024"; Racing Spark Plug |
| 2003 | Yamaha | YZ125 | -L | -- | Race Kart; Gap 0.024"; Racing Spark Plug |
| 2002 | Yamaha | YZ125 | -L | -- | Race Kart; Gap 0.024"; Racing Spark Plug |
| 2001 | Yamaha | YZ125 | -L | -- | Race Kart; Gap 0.024"; Racing Spark Plug |
| 2000 | Yamaha | YZ125 | -L | -- | Race Kart; Gap 0.024"; Racing Spark Plug |
| 1999 | Yamaha | YZ125 | -L | -- | Race Kart; Gap 0.024"; Racing Spark Plug |
| 1993 | Yamaha | YZ125 | -L | -- | Race Kart; Gap 0.024"; Racing Spark Plug |
| 1992 | Yamaha | YZ125 | -L | -- | Race Kart; Gap 0.024"; Racing Spark Plug |
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