NGK BPZ8H-N-10 V-Power Spark Plug - 4495

NGK BPZ8H-N-10 V-Power Spark Plug – 4495

The NGK BPZ8H-N-10 V-Power Spark Plug, stock number 4495, is a proven replacement for select Mercury and Mariner outboard engines. Designed for reliable ignition in two-stroke marine applications, its V-groove center electrode helps concentrate the spark at the edge of the electrode for dependable combustion, smooth acceleration, and consistent performance throughout the RPM range.

Built around a copper-core center electrode with a nickel firing tip, the BPZ8H-N-10 provides effective heat transfer while standing up to the demanding operating conditions found in outboard engines. Its special resistor design also helps control electrical interference that can affect onboard electronics.

A worn or fouled plug can contribute to difficult starting, rough idle, hesitation, reduced power, and poor fuel efficiency. Installing fresh NGK 4495 spark plugs during routine maintenance helps restore proper ignition and keeps compatible Mercury-powered boats running as intended.

Spark Plug Specifications

• Manufacturer: NGK

• Part Number: BPZ8H-N-10

• NGK Stock Number: 4495

• Design: V-Power

• Center Electrode Core: Copper

• Center Electrode Tip: Nickel with V-groove

• Heat Range: 8

• Thread Diameter: 14 mm

• Thread Reach: 12.7 mm

• Hex Size: 13/16"

• Seat Type: Gasket / flat seat

• Pre-Gap: .040" / 1.0 mm

• Ground Electrode: Single

• Resistor Type: Special resistor

• Sold Individually

Common Mercury & Mariner Engine Applications

The NGK BPZ8H-N-10 / 4495 is used in select Mercury and Mariner outboard engines, including:

• Mercury 6 HP 2-Stroke

• Mercury 8 HP 2-Stroke

• Mercury 20 HP 2-Stroke

• Mercury 25 HP 2-Stroke

• Mercury 30 HP applications

• Mercury 100 HP 2-Stroke

• Mercury 115 HP 2-Stroke

• Mercury 125 HP 2-Stroke

• Mercury 225 HP 3.0L applications

• Select Mariner 2-Stroke outboards

Application years vary significantly by horsepower and engine family. For example, the BPZ8H-N-10 is listed for select Mercury 20 HP and 25 HP two-strokes from the early 1990s and 2001–2006, along with certain larger Mercury two-stroke engines.

Common Boat Applications

Because Mercury and Mariner outboards were installed by many boat manufacturers, the NGK 4495 may be found in compatible engine packages used on boats such as:

Boston Whaler

• Boston Whaler Sport

• Boston Whaler Montauk

• Boston Whaler Dauntless

Tracker

• Tracker Pro Team

• Tracker Pro Guide

• Tracker Targa

Lund

• Lund Rebel

• Lund Adventure

• Lund Pro-V

Sea Pro

• Sea Pro Center Console models

• Sea Pro Bay Boat models

Carolina Skiff

• Carolina Skiff J-Series

• Carolina Skiff DLX Series

• Carolina Skiff center console models

Bayliner

• Bayliner Capri

• Bayliner Trophy

• Select Mercury-powered runabout models

Additional applications may include older Ranger, Nitro, Key West, Mako, Grady-White, Sea Ray, Princecraft, Lowe, Alumacraft, and other boats originally equipped with a compatible Mercury or Mariner outboard.

Mercury / Quicksilver Cross References

The NGK BPZ8H-N-10 / 4495 cross-references with select Mercury Marine spark plug numbers, including:

• Mercury 33-816837Q

• Mercury 33-816837B2

• Mercury / MerCruiser 33-8168372

• NGK BPZ8H-N-10

• NGK 4495

Always verify the original plug number before using a cross-reference for replacement.

Key Features

• Genuine NGK BPZ8H-N-10 V-Power spark plug

• NGK stock number 4495

• Designed for select Mercury and Mariner marine engines

• V-groove electrode promotes dependable ignition

• Copper core provides efficient heat transfer

• Special resistor construction helps suppress electrical interference

• .040-inch factory gap specification

• Ideal for routine outboard maintenance and tune-ups

• Proven replacement for select Mercury 33-816837-series plugs

Reliable Performance for Mercury Two-Stroke Outboards

Two-stroke outboards depend heavily on proper spark plug condition for clean starting, smooth acceleration, and consistent power. Carbon deposits, electrode wear, or incorrect plug specifications can quickly affect how an engine performs. The NGK BPZ8H-N-10 provides a proven replacement option for compatible Mercury and Mariner engines, making it an excellent choice for seasonal service or a complete ignition tune-up.

Fitment Note: Mercury used different spark plugs within the same horsepower ranges depending on model year, serial number, and engine configuration. Do not determine compatibility by boat model alone. Verify NGK BPZ8H-N-10 / stock #4495 against your Mercury or Mariner engine model, serial-number range, or original spark plug before ordering.