# Valve stem to guide clearance — standard and maximum (NA6)

Canonical URL: https://miatatorque.com/spec/valve-stem-guide-clearance-na6/

Applicability: NA 1990–1993 (B6) — Other years inferred from 1990 factory evidence.

Confidence: fsm

Clearance
IN: 0.025–0.060 mm (0.0010–0.0024 in)
EX: 0.030–0.065 mm (0.0012–0.0026 in)
Maximum: 0.20 mm (0.008 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": "valve-stem-guide-clearance-na6",
  "name": "Valve stem to guide clearance — standard and maximum (NA6)",
  "aliases": [],
  "applies_to": [
    {
      "gen": "NA",
      "years": [
        1990,
        1993
      ],
      "engines": [
        "B6"
      ],
      "note": "Other years inferred from 1990 factory evidence."
    }
  ],
  "kind": "non-torque",
  "value_text": "Clearance\nIN: 0.025–0.060 mm (0.0010–0.0024 in)\nEX: 0.030–0.065 mm (0.0012–0.0026 in)\nMaximum: 0.20 mm (0.008 in)",
  "procedure": {
    "notes": "Subtract the measured valve-stem outside diameter from the corresponding guide inside diameter. Replace valve and/or guide when clearance exceeds specification."
  },
  "confidence": "fsm",
  "sources": [
    {
      "source": "fsm-1990",
      "page": "B–49 (PDF p. 76)",
      "as_printed": "Clearance\nIN: 0.025—0.060mm (0.0010—0.0024 in)\nEX: 0.030—0.065mm (0.0012—0.0026 in)\nMaximum: 0.20mm (0.008 in)",
      "verified_years": [
        1990,
        1990
      ],
      "document": {
        "id": "fsm-1990",
        "tier": 1,
        "title": "1990 Mazda MX-5 Miata Workshop Manual",
        "part_number": "1193-10-89C",
        "covers": [
          {
            "gen": "NA",
            "years": [
              1990,
              1990
            ],
            "engines": [
              "B6"
            ]
          }
        ],
        "url": "https://archive.org/details/1990-mazda-mx-5-miata-workshop-manual_202411"
      }
    }
  ],
  "jobs": [],
  "system": "engine",
  "component": "inventory-pass-2026-10",
  "componentName": "Service measurements and fasteners",
  "sequence_diagrams": [],
  "url": "https://miatatorque.com/spec/valve-stem-guide-clearance-na6/"
}
```