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Marine & Outboard Spark Plugs

NGK Surface Gap Spark Plug BUZHW-2 (2173)

SKU: GB-BUZHW-2

$31.35
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The NGK BUZHW-2 (Stock No. 2173) is a resistor-type surface-gap spark plug designed for selected Mercury and Mariner 2-stroke outboard motors. Its surface-discharge electrode configuration provides reliable ignition without a conventional adjustable ground electrode, while the built-in suppression resistor helps reduce electrical interference. BUZHW-2 is the resistor alternative to BUHW-2 in numerous older Mercury/Mariner outboard applications.

Key benefits

Key Benefits

  • - Surface-gap / surface-discharge design
  • - Designed for selected 2-stroke outboard motors
  • - Built-in resistor for electrical interference suppression
  • - No conventional projecting ground electrode
  • - No manual electrode-gap adjustment
  • - Short 12.7 mm thread reach
  • - Flat gasket seat
  • - Solid terminal
  • - Direct resistor alternative to NGK BUHW-2
  • - Mercury/Mariner part number 33-14103570

Specifications & Dimensions

  • - Brand: NGK
  • - Part Number: BUZHW-2
  • - NGK Stock Number: 2173
  • - Spark Plug Type: Resistor surface-gap
  • - Thread Diameter: 14 mm / 0.551"
  • - Thread Size: M14 × 1.25
  • - Thread Pitch: 1.25 mm / 0.049"
  • - Thread Reach: 12.7 mm / 0.500"
  • - Hex / Spanner Size: 20.8–21 mm / 13/16"
  • - Seat Type: Flat / gasket seat
  • - Resistor: Yes
  • - Electrode Type: Surface discharge / surface gap
  • - Electrode Projection: Non-projected
  • - Conventional Ground Electrode: None
  • - Adjustable Spark Gap: No
  • - Terminal: Solid
  • - Sealing Washer: Yes

Compatible Outboard Motors

  • Mercury Outboards
  • - Mercury 4.5 HP / 45 – 1-cylinder – Australian serial 8026540 and up
  • - Mercury 7.5 HP / 75 – Australian serial 8051350–8058019
  • - Mercury 9.8 HP / 110 – Australian serial 8050625–8057544
  • - Mercury 20 HP / 200 – Australian serial 8006265 and up
  • - Mercury 80 HP / 800 – 4-cylinder – Australian serial 8050200 and up

Cross-Reference Spark Plugs & Part Numbers

  • - NGK: BUZHW-2
  • - NGK Stock Number: 2173
  • - Mercury / Mariner: 33-14103570
  • - Mercury: 14103Q
  • - Mercury: 33-838
  • - NGK non-resistor counterpart: BUHW-2
  • - Mercury BUHW-2: 33-97182Q
  • - Champion: L78V
  • - Champion: QL78V
  • - OMC: 771770

Important Fitment Information

  • BUZHW-2 is a surface-gap plug and should not be manually gapped. There is no conventional projecting side electrode to bend.
  • It is also important not to confuse these closely related plugs
  • - BUZHW-2 – resistor surface-gap
  • - BUHW-2 – non-resistor surface-gap counterpart
  • - BUZHW – different application version
  • - BUHW – non-resistor version of BUZHW applications
  • - BUZ8H – different heat range/application family
  • Mercury's catalogue demonstrates this distinction clearly. For example, some 7.5 HP and 9.8 HP serial ranges specify BUZHW, while adjacent serial ranges specify BUZHW-2

Signs the Spark Plug Needs Replacing

  • - Difficult starting
  • - Rough running
  • - Engine misfire
  • - Hesitation during acceleration
  • - Reduced high-RPM performance
  • - Loss of engine power
  • - Excessive carbon deposits
  • - Oil fouling
  • - Corrosion
  • - Cracked ceramic insulator
  • - Damage or excessive wear around the surface-gap firing area

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