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NGK 90398 Spark Plug
| Brand | NGK 90398 |
|---|---|
| Resistance | 5000 |
| Ground Electrode Tip Design | Standard |
| Ground Configuration | Standard |
| Ground Electrode Core Material | Nickel |
| Electrical Terminal Type | Stud |
| Center Electrode Core Material | Copper |
| Center Electrode Tip Material | Nickel |
| Pre-Gap Size | 0.016 |
| Ground Electrode Quantity | 2 |
| Hex Size | 14 |
| Insulator Height | 49.00 |
| Manufacturer Heat Range | 8 |
| Seat Type | Flat |
| Reach | 26.5 |
| Thread Diameter | 10.00 |
| Resistor Type | Yes |
| Part Number | Lmar8e-j |
| Stock Number | 90398 |
| Product line | Standard Spark Plug |
| Fits | Yamaha · 4 vehicles |
OE-standard design. Built to original equipment standards for consistent ignition service.
Copper core construction. Copper center electrode core with nickel tips for stable conductivity.
Resistor spark plug. Helps reduce electrical noise in the ignition system.
Cross-references NGK 90398 for the same application. See all 1.
Will it fit your vehicle?
Free return shipping if it doesn't fit.
NGK 90398 Standard Spark Plug
NGK 90398 is a standard spark plug built with a copper center electrode core, nickel center and ground electrode tips, and a resistor design. It is specified with a 0.016-inch pre-gap, flat seat, and 10 mm thread diameter for precise ignition service.
Key Features
- Standard spark plug design for consistent ignition performance.
- Copper core with nickel electrode materials for stable conductivity and wear resistance.
- Resistor construction helps control electrical noise in the ignition system.
- Flat seat and 26.5 reach for the specified application.
- Part number 90398, also identified as LMAR8E-J.
Detailed Description
This NGK spark plug is engineered to OE standards and reflects the brand’s long-standing role as a major original equipment supplier. The 90398 spark plug uses a stud terminal, 14 mm hex, and standard ground configuration, making it a precise replacement for the listed applications. For buyers searching for a Yamaha WR250F spark plug or Yamaha YZ250FX spark plug, this part number 90398 matches the specified fitment and factory-style gap requirement.
NGK’s Standard Spark Plug line focuses on dependable ignition service with materials and dimensions selected for controlled spark delivery and consistent operation. The LMAR8E-J / 90398 designation helps confirm the exact replacement when cross-checking catalog listings or service references.
What It Is Used For
- Restoring weak or inconsistent spark output.
- Replacing a worn plug with incorrect gap or electrode wear.
- Addressing hard starting caused by ignition degradation.
- Correcting misfire symptoms tied to plug condition.
Installation Notes and Tips
Fits 2020-2021 Yamaha WR250F, N/A. Fits 2020-2021 Yamaha YZ250FX, N/A. Verify the 0.016-inch gap before installation and confirm the thread diameter, reach, and seat type match the engine specification. Use the part number 90398 and LMAR8E-J to confirm the correct application during service lookup.
Quality Assurance
NGK states that it manufactures spark plugs to original equipment standards and supports a broad range of automotive and powersports applications. The brand’s OE supplier background and North American manufacturing presence support consistent product control and application accuracy.
| Year | Make | Model | Liters | Cylinders | Notes |
|---|---|---|---|---|---|
| 2021 | Yamaha | WR250F | -L | -- | Gap 0.016"; Actual OE Manufacturer; Standard Spark Plug |
| 2021 | Yamaha | YZ250FX | -L | -- | Gap 0.016"; Actual OE Manufacturer; Standard Spark Plug |
| 2020 | Yamaha | WR250F | -L | -- | Gap 0.016"; Actual OE Manufacturer; Standard Spark Plug |
| 2020 | Yamaha | YZ250FX | -L | -- | Gap 0.016"; Actual OE Manufacturer; Standard Spark Plug |
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