Mercury – Quicksilver NGK BPR5EFS-13 Spark Plug | Ignition | 33-8M0095454

Overview

On the MerCruiser 4.5L and 6.2L engines, the spark plugs carry a lot of the load. When they start getting worn, the engine usually tells you—idle gets a little rough, throttle feels mushy, or the motor just doesn’t have the same bite when you push it. These NGK BPR5EFS-13 plugs are the exact plugs Mercury calls for on these engines. They hold up well to heat, vibration, and long days on the water, and they keep the ignition clean and steady so the engine runs the way it should.

Key Features

 • Resistor-Style Plug – Helps keep ignition noise from bleeding into radios and gauges.
 • Copper-Core Electrode – Moves heat well and keeps the spark strong and predictable.
 • OEM-Matched Specs – Same plug Mercury designed these engines around.
 • Good Long-Term Wear – Holds its gap longer instead of falling off over time.

Engine & Boat Compatibility

 • MerCruiser 4.5L engines
 • MerCruiser 6.2L engines
 • Sterndrive platforms
 • EFI ignition systems

Performance & Practical Benefits

A fresh set of plugs usually brings a noticeable improvement. Idle smooths out, the engine fires quicker, and throttle response feels cleaner. These copper-core NGKs help the engine keep its timing tight, especially under load, which means better mid-range pull and more consistent power when you’re running a heavy boat or towing. It’s a simple bit of maintenance that pays off right away.

Why Buy OEM

Spark plugs aren’t a place to experiment. Using the correct plug ensures the heat range, spark strength, and longevity match what MerCruiser built the engine around. Off-brand or “close enough” plugs can cause misfires, poor fuel burn, or long-term internal damage. OEM-spec NGKs keep things predictable.

FAQ

Q1: How do I know the plugs are getting tired?
A: Harder starts, rougher idle, hesitation when throttling up, or the engine losing some of its punch.

Q2: Do I need to gap these plugs?
A: Yes—always check your owner’s manual. Even new plugs should be verified.

Q3: Will these help reduce interference in electronics?
A: Yep—the resistor design helps keep radios and screens cleaner.

Q4: How often should I replace them?
A: Follow the MerCruiser schedule, but boats run in tougher conditions—many skippers change them earlier.

Q5: What happens if I run the wrong plug?
A: You risk misfires, poor performance, or even engine damage from improper heat range.