# Main bearing oil clearance — maximum (NA6)

Canonical URL: https://miatatorque.com/spec/main-bearing-oil-clearance-limit-na6/

Applicability: NA 1990–1993 (B6) — 1991–1993 applicability inferred from 1990 within the owner-approved NA6 group.

Confidence: fsm

0.10 mm (0.004 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": "main-bearing-oil-clearance-limit-na6",
  "name": "Main bearing oil clearance — maximum (NA6)",
  "aliases": [],
  "applies_to": [
    {
      "gen": "NA",
      "years": [
        1990,
        1993
      ],
      "engines": [
        "B6"
      ],
      "note": "1991–1993 applicability inferred from 1990 within the owner-approved NA6 group."
    }
  ],
  "kind": "non-torque",
  "value_text": "0.10 mm (0.004 in)",
  "procedure": {
    "notes": "Measure Plastigage at each journal at its widest point for the smallest clearance and narrowest point for the largest clearance. Follow B–63–64 inspection procedure."
  },
  "confidence": "fsm",
  "sources": [
    {
      "source": "fsm-1990",
      "page": "B–64 (PDF p. 91)",
      "as_printed": "0.10mm (0.004 in)",
      "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": "reaudit-settings-na6",
  "componentName": "NA6 crankshaft inspection settings",
  "sequence_diagrams": [],
  "url": "https://miatatorque.com/spec/main-bearing-oil-clearance-limit-na6/"
}
```