# Spark plug gap (NB1)

Canonical URL: https://miatatorque.com/spec/spark-plug-gap-nb1/

Applicability: NB 1999–2000 (BP-4W) — Other years in this family inferred from 1999 factory evidence with owner approval; actual-year verification is separate.

Confidence: fsm

1.0–1.1 mm (0.040–0.043 in)

Always confirm against your factory manual. Match every restriction and follow all stages and procedure notes. Disputed claims must not be automatically resolved. The complete record below preserves every printed unit, source claim and procedure.

```json
{
  "id": "spark-plug-gap-nb1",
  "name": "Spark plug gap (NB1)",
  "aliases": [],
  "applies_to": [
    {
      "gen": "NB",
      "years": [
        1999,
        2000
      ],
      "engines": [
        "BP-4W"
      ],
      "note": "Other years in this family inferred from 1999 factory evidence with owner approval; actual-year verification is separate."
    }
  ],
  "kind": "non-torque",
  "value_text": "1.0–1.1 mm (0.040–0.043 in)",
  "procedure": {
    "notes": "Factory plug gap for the naturally aspirated engine; the Mazdaspeed plug has a separate smaller gap."
  },
  "confidence": "fsm",
  "sources": [
    {
      "source": "fsm-1999",
      "page": "01–50–3 (PDF p. 314)",
      "as_printed": "Spark plug\nPlug gap\n(mm {in})\n1.0—1.1 {0.040—0.043}",
      "verified_years": [
        1999,
        1999
      ],
      "document": {
        "id": "fsm-1999",
        "tier": 1,
        "title": "1999 Mazda MX-5 Miata Workshop Manual",
        "covers": [
          {
            "gen": "NB",
            "years": [
              1999,
              2000
            ],
            "engines": [
              "BP-4W"
            ]
          }
        ],
        "url": "https://www.mellens.net/mazda/Mazda-Miata-1999-2001.pdf"
      }
    }
  ],
  "jobs": [],
  "system": "ignition-electrical",
  "component": "gap-followup-2026-10",
  "componentName": "Additional factory manual gap audit",
  "sequence_diagrams": [],
  "url": "https://miatatorque.com/spec/spark-plug-gap-nb1/"
}
```