Marine spark plugs are essential components designed to ignite the fuel-air mixture in marine engines, ensuring smooth and efficient performance. Built for outboard and inboard engines, they withstand harsh marine conditions, including exposure to saltwater and humidity.
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1-2 weeks delivery time NGK BR9ES (Osculati 47.558.75) is a cold-range, long-reach resistor spark plug with M14 × 1.25 mm thread, 19 mm reach, 20.8 mm hex, and factory-set 0.7 mm gap. Designed for high-RPM 2-stroke marine engines by Yamaha, Suzuki, Mercury, Tohatsu, Selva, Honda, and Mariner. The built-in resistor protects onboard electronics from EMI. No direct Champion equivalent.
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$ 11.89
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1-2 weeks delivery time Osculati 47.558.07 – NGK BR9HS-10 is a resistor-type spark plug designed for high-RPM 2-stroke outboards from brands like Yamaha, Mercury, Suzuki, Tohatsu, Mariner, Selva, and Honda. With a 14 mm thread, 12.7 mm (1/2") reach, 20.8 mm (13/16") hex, and a 1.0 mm factory-set gap, it ensures strong, clean ignition and protects sensitive onboard electronics. Equivalent to Champion QL77JC4.
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$ 12.38
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1-2 weeks delivery time NGK BU8H (Osculati 47.558.55) is a non-resistor marine spark plug with M14 × 1.25 mm thread, 9.5 mm reach, and a 21 mm hex. Designed for high-load 2-stroke outboards by Yamaha, Mercury, Mariner, Suzuki, Tohatsu, Selva, and Honda. Its wide housing and hot heat range ensure consistent ignition in engines prone to fouling. Equivalent to Champion L6VC.
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$ 17.99
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1-2 weeks delivery time NGK BZ7HS-10 (Osculati 47.558.63) is a short-reach resistor spark plug with M14 × 1.25 mm thread, 12.7 mm reach, 20.8 mm hex, and a 1.0 mm preset gap. Specifically engineered for 2-stroke marine engines from Yamaha, Mercury, Suzuki, Tohatsu, Selva, and Honda. Its zinc-dipped shell resists corrosion in saltwater environments. No direct Champion equivalent.
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$ 23.10
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1-2 weeks delivery time NGK CPR6EA-9 (Osculati 47.558.62) is a resistor spark plug featuring M10 × 1.0 mm thread, 19 mm reach, 16 mm hex, and a factory-set 0.9 mm gap. Its compact body and projected insulator tip make it ideal for tight-fitting 4-stroke outboards by Yamaha, Honda, Mercury, Suzuki, Tohatsu, Selva, and Mariner. Offers stable combustion, reduced fouling, and EMI protection. No Champion equivalent.
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$ 20.62
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1-2 weeks delivery time Osculati 47.558.15 – NGK CR4HSB is a compact resistor-type spark plug for small-displacement marine outboards. It features a 10 mm thread, 12.7 mm (1/2") reach, 16 mm hex, and a projected-tip copper core electrode. Common in 4-stroke outboards from Yamaha, Mercury, Honda, Tohatsu, and Suzuki. No Champion equivalent.
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$ 12.76
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1-2 weeks delivery time NGK CR5EH-9 (Osculati 47.558.53) is a compact resistor-type spark plug with M10 × 1.0 mm thread, 19 mm reach, 14 mm hex, and a factory-set 0.9 mm gap. Designed for small-displacement 4-stroke marine outboards from Yamaha, Mercury, Mariner, Suzuki, Tohatsu, Selva, and Honda. Provides precise ignition, reduced fouling, and full compatibility with Champion 79Y.
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$ 26.88
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1-2 weeks delivery time NGK CR5HSB (Osculati 47.558.50) is a compact resistor spark plug with M10 × 1.0 mm thread, 12.7 mm reach, 16 mm hex, and a factory-set 0.7–0.8 mm gap. Designed for small-displacement 4-stroke outboards from Yamaha, Mercury, Mariner, Suzuki, Tohatsu, Selva, and Honda. Provides excellent anti-fouling performance and EMI suppression. Equivalent to Champion 79Y.
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$ 12.56
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1-2 weeks delivery time Osculati 47.558.16 – NGK CR6E is a resistor-type spark plug with a 10 mm thread, 19 mm (3/4") reach, and 16 mm hex. It features a projected copper core electrode and is factory-gapped for 4-stroke marine outboards from Honda, Yamaha, Suzuki, Mercury, Mariner, Tohatsu, and Selva. No Champion equivalent.
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$ 20.42
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1-2 weeks delivery time NGK CR6HS (Osculati 47.558.40) is a compact, resistor-type spark plug with a 10 mm thread, 12.7 mm reach, 16 mm hex, and a 0.7–0.8 mm factory gap. Designed for small 2- and 4-stroke marine engines from Yamaha, Mercury, Mariner, Suzuki, Tohatsu, Selva, and Honda. It suppresses EMI and ensures clean, stable combustion. Cross-compatible with Champion Z9Y.
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$ 13.05
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1-2 weeks delivery time The Osculati 47.558.95 – NGK CR6HSA spark plug is a compact, resistor-type ignition component designed for modern small-displacement outboard engines. With a 10 mm thread diameter, 12.7 mm (1/2") reach, and a solid terminal, it provides optimal ignition performance in compact marine motors. Widely compatible with outboard brands such as Yamaha, Suzuki, Mercury, Tohatsu, Selva, Honda, and Mariner, this plug ensures reliable starts and extended durability. Champion cross-reference: P-RZ-9HC.
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$ 9.70
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1-2 weeks delivery time NGK CR9EB (Osculati 47.558.77) is a short-reach, resistor-type spark plug with M10 × 1.0 mm thread, 19 mm reach, 16 mm hex, and 0.7 mm preset gap. Built for high-revving marine 4-stroke engines by Yamaha, Honda, Suzuki, Mercury, Tohatsu, Selva, and Mariner. Its cold heat range (9) resists detonation under load. Direct Champion equivalent: RG4-PHP.
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$ 20.76
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1-2 weeks delivery time NGK DCPR6E (Osculati 47.558.48) is a resistor-type spark plug with M12 × 1.25 mm thread, 19 mm reach, 16 mm hex size, and 0.9 mm factory-set gap. Designed for high-efficiency 4-stroke outboards from Yamaha, Mercury, Mariner, Suzuki, Tohatsu, Selva, and Honda. Its compact profile with a projected tip ensures clean combustion and precise ignition. Cross-compatible with Champion RA8HC.
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$ 20.35
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1-2 weeks delivery time NGK DCPR7E (Osculati 47.558.32), often labeled as RA8-H10 in OEM marine catalogs, is a precision resistor spark plug with a 12 mm thread, 19 mm reach, 16 mm hex size, and a 0.9 mm gap. Suitable for Yamaha, Mercury, Mariner, Suzuki, Tohatsu, Selva, and Honda outboards. Equivalent to Champion RA8HC. Optimized for 4-stroke marine engines with compact cylinder heads and electronic ignition systems.
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$ 19.98
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1-2 weeks delivery time NGK DPR6EA-9 (Osculati 47.558.31) is a marine-grade spark plug with a 14 mm thread, 19 mm reach, 18 mm hex size, and a factory-set 0.9 mm gap. Designed for use in Yamaha, Mercury, Mariner, Suzuki, Tohatsu, Selva, and Honda outboards, this resistor-type plug features a projected insulator for better anti-fouling and matches Champion RA8HC. Recommended for high-performance 4-stroke engines in marine environments.
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$ 10.43
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1-2 weeks delivery time NGK DPR6EB-9 (Osculati 47.558.42) is a precision resistor-type spark plug featuring a 14 mm thread, 19 mm reach, compact 18 mm hex, and a 0.9 mm preset gap. Commonly used in 4-stroke marine engines by Yamaha, Mercury, Mariner, Suzuki, Tohatsu, Selva, and Honda. Optimized for electronic ignition systems. Interchangeable with Champion RA8HC.
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$ 13.15
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1-2 weeks delivery time Osculati 47.558.17 – NGK DR5HS is a resistor-type spark plug with a 14 mm thread, 12.7 mm (1/2") reach, and 20.8 mm (13/16") hex. Designed for smooth combustion and RFI protection in 2-stroke marine engines by Yamaha, Mercury, Suzuki, Tohatsu, Selva, Mariner, and Honda. Champion equivalent: P10Y.
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$ 13.05
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1-2 weeks delivery time Osculati 47.558.18 – NGK DR6HS is a resistor-type spark plug with a 14 mm thread, 12.7 mm (1/2") reach, and 20.8 mm (13/16") hex. Designed for 2-stroke marine outboards by Yamaha, Mercury, Mariner, Suzuki, Tohatsu, Selva, and Honda. It provides RFI protection and stable combustion with medium heat range. Champion equivalent: P8Y.
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$ 12.61
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1-2 weeks delivery time Osculati 47.558.19 – NGK DR7EA is a resistor-type spark plug with a 12 mm thread, 19 mm (3/4") reach, and 18 mm hex, ideal for modern 4-stroke marine engines. It offers clean combustion, RFI suppression, and durability in Yamaha, Mercury, Suzuki, Honda, Tohatsu, Selva, and Mariner engines. Champion equivalent: RA8HC.
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$ 12.86
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1-2 weeks delivery time NGK ILFR6GE (Osculati 47.558.60) is a premium iridium spark plug with M14 × 1.25 mm thread, 19 mm reach, 16 mm hex, and a factory-set 1.1 mm gap. Built for high-efficiency 4-stroke outboard engines from Mercury, Yamaha, Suzuki, Honda, Tohatsu, Selva, and Mariner. Features iridium center electrode and platinum ground electrode for extended life and precise ignition under all loads. No direct Champion equivalent.
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$ 53.94
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Why is selecting the right spark plug critical for optimal engine performance in marine applications?
Selecting the right spark plug is critical for optimal engine performance in marine applications because it ensures proper ignition, efficient fuel combustion, and reliable operation in harsh conditions. Using the correct part number guarantees compatibility with the engine, maximizing performance and preventing potential damage. This careful selection increases engine efficiency, providing the best experience on the water.
Choosing the correct part number from trusted brands like Champion Spark Plugs helps maintain engine health and ensures smooth, efficient operation on the water.
How do marine spark plugs differ from standard auto parts used in cars?
Marine spark plugs differ from standard auto parts because they are specifically designed to withstand the harsh conditions of marine environments, including exposure to saltwater, humidity, and extreme temperature fluctuations. They often feature corrosion-resistant materials and a more robust construction to handle the unique demands of outboard and inboard engines. These features ensure reliable ignition and optimal performance even in challenging marine applications.