Diagnostic Guide

Smoke From Marine Engine — What It Means

Different colors mean different things. Don't ignore it.

Different colors mean different things. Don't ignore it.

What to Check

1

White smoke

Steam from cooling water leak (head gasket, exhaust riser) or unburned fuel from a misfire.

2

Blue smoke

Burning oil. Worn rings, valve guides, or in 2-stroke outboards, just normal.

3

Black smoke

Too much fuel. Clogged air intake, bad injector, or engine running rich.

When to Call Us

Smoke from any 4-stroke engine that's not normal start-up steam needs diagnosis — we run scan tools and compression tests to find the cause.

Services That Fix This

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Bring your boat to our covered shop in San Rafael for full-service repair, maintenance, paint, and refits. Call (415) 524-5194 or send a message — we respond same day.

Call (415) 524-5194