Yamaha spark plug replacement

Spark plugs are one of the biggest causes of down time in the summer. They wear steadily and quietly, and the engine runs fine right up until it does not. Here is what the job is, why two years is the number, and how to book it.

What's in it

• Every plug replaced with Yamaha's specified plug for that engine, gapped and torqued — not whatever is on the shelf that fits the thread.
• Coils and boots inspected as each one comes off. A coil that has been working too hard shows it, and a cracked boot lets water in.
• The old set read before it goes in the bin. What a plug looks like says how the cylinder has been running, and it is the cheapest diagnosis there is.
• Yamaha diagnostics on the way out, so a misfire the computer logged is cleared and not left to confuse the next visit.

Why two years

A plug wears a little every time it fires, and as the gap opens the coil has to push harder to jump it. Left in too long a set takes ignition components with it when it finally goes — which turns a small scheduled job into a diagnosis and a parts order in the middle of the season. Replacing them every two years or 200 hours keeps you off the phone in July.

What we usually find

Most sets that come out at two years are worn but honest. The ones that come out at four or five are the ones with a coil on the same order — and on an engine that has been run on old fuel, a fouled set that tells us the vapor separator wants looking at too.

How it's quoted

We quote it the same day you ask. The number depends on your engine, and the service writer confirms it with you before any work begins. It is often done alongside the anodes, which share the two-year interval.

Yamaha Marine Service Pro Elite dealer — five certified technicians, one of them a Master Tech. 💬 Ask the assistant or call (302) 436-1737.