# 25-60 HP 4-Stroke — Outboard motor service specifications by brand and model

For 25-60 HP 4-Stroke, brand is Mercury; spark plug is NGK BPR6ES; gap is 0.040" (1.0mm), recorded from its source on 2026-08-05.

- **Brand:** Mercury
- **Model / range:** 25-60 HP 4-Stroke _(verified: appears in the quote below)_
- **Spark plug:** NGK BPR6ES _(verified: appears in the quote below)_
- **Gap:** 0.040" (1.0mm) _(verified: appears in the quote below)_

## What the source says

> 25-60 HP 4-Stroke | NGK BPR6ES | 0.040" (1.0mm)

## Source

- https://seasierra.com/blogs/outboard-101/outboard-spark-plug-replacement-the-right-plugs-and-gaps

Last verified: 2026-08-05. Review by: 2028-08-04.
Part of [Outboard motor service specifications by brand and model](https://referencesource.org/outboard-motor-service-specs/).