Back to catalogue
Marine & Outboard Spark Plugs

NGK Nickel Spark Plug DR5HS (4623)

SKU: GB-DR5HS

$8.80
Request a quote

The NGK DR5HS (Stock No. 4623) is a resistor spark plug used in selected Honda four-stroke outboard motors, particularly earlier BF7.5, BF8, BF9.9 and BF100/10 HP families. It features an M12 × 1.25 thread, 12.7 mm reach and 18 mm hex. Its nickel electrode, copper-core construction and built-in resistor provide reliable ignition and effective heat transfer in marine applications.

Key benefits

Key Benefits

  • - NGK Stock Number: 4623
  • - Confirmed Honda four-stroke outboard applications
  • - Built-in resistor for electrical interference suppression
  • - Nickel electrode with copper-core construction
  • - M12 × 1.25 thread
  • - 12.7 mm / ½" reach
  • - 18 mm hex
  • - NGK heat range 5
  • - Flat gasket seat
  • - Compact short-reach design

Specifications & Dimensions

  • - Brand: NGK
  • - Part Number: DR5HS
  • - NGK Stock Number: 4623
  • - Thread Diameter: 12 mm / 0.472"
  • - Thread Size: M12 × 1.25
  • - Thread Reach: 12.7 mm / 0.500"
  • - Hex / Spanner Size: 18 mm / 0.709"
  • - NGK Heat Range: 5
  • - Application Gap: typically 0.6–0.7 mm / 0.024–0.028", depending on engine specification
  • - Seat Type: Flat / gasket
  • - Resistor: Yes
  • - Centre Electrode: Nickel
  • - Centre Electrode Core: Copper
  • - Ground Electrode: Nickel
  • - Ground Electrodes: 1
  • - Terminal: Threaded
  • - Sealing Washer: Yes

Compatible Outboard Motors

  • Honda 7.5 HP
  • - Honda B75 – 7.5 HP
  • - Honda BF75 – 7.5 HP
  • NGK specifically lists the B75 7.5 HP two-cylinder four-stroke from 1977 with DR5HS.

Honda 8 HP

  • - Honda BF8 – 8 HP, earlier generation
  • - Honda BF8A – 8 HP
  • - Honda BF8A3
  • - Honda BF8A4
  • - Honda BF8A5
  • - Honda BF8A6
  • - Honda BF8AK0
  • - Honda BF8AY
  • - Honda BF8C – 8 HP
  • NGK's current 2024–2025 catalogue specifically lists the BF8A family with DR5HS Stock No. 4623, including BF8A3, BF8A4, BF8A5, BF8A6, BF8AK0 and BF8AY applications.

Honda 9.8 / 9.9 HP

  • - Honda BF100 – 9.8 HP
  • - Honda BF9.9A – 9.9 HP, through 2000
  • NGK specifically confirms BF9.9A two-cylinder four-stroke through 2000 with DR5HS.

Honda 10 HP

  • - Honda BF100 – 10 HP
  • - Honda BF100E – 10 HP
  • NGK directly lists DR5HS for the BF100 10 HP two-cylinder four-stroke.

Important Honda Model Change

  • - BF9.9A through 2000 → DR5HS
  • - BF9.9D from 2001 → CR5EH-9
  • - BF10 / BF10B1 / BF10D from 2001 → CR5EH-9

Johnson Outboards

  • Marine application data also identifies DR5HS for selected Johnson 8 HP four-stroke SOHC engines from approximately 2002 onward. Exact model/year should be checked before ordering.

Cross-Reference Spark Plugs & Part Numbers

  • - NGK: DR5HS
  • - NGK Stock Number: 4623
  • - Honda: 98066-55716
  • - Champion: RP10HC
  • - Mercury reference: 852868140

Signs the Spark Plug Needs Replacing

  • - Difficult starting
  • - Rough or unstable idle
  • - Engine misfire
  • - Hesitation during acceleration
  • - Reduced engine power
  • - Increased fuel consumption
  • - Carbon deposits
  • - Fuel or oil fouling
  • - Excessive electrode wear
  • - Corrosion
  • - Cracked ceramic insulator

Shipping

Ships Australia-wide