{"product_id":"west-1151","title":"NGK Iridium IX Spark Plug - TR55IX","description":"\u003cp\u003eThe \u003cstrong\u003eNGK TR55IX\u003c\/strong\u003e is an Iridium IX spark plug used in select automotive, marine, performance, and equipment applications where the engine manufacturer specifies the \u003cstrong\u003eTR55IX \/ NGK 7164\u003c\/strong\u003e plug profile. It is commonly used as an iridium upgrade from standard nickel TR-series plugs when the required reach, tapered seat, heat range, terminal style, and gap match the engine's factory specification.\u003c\/p\u003e\n\u003cp\u003eThis plug features NGK's fine-wire iridium center electrode design for strong ignitability, stable spark performance, and improved resistance to fouling in compatible engines.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eKey Features\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eGenuine NGK Iridium IX spark plug.\u003c\/li\u003e\n\u003cli\u003eNGK part number: \u003cstrong\u003eTR55IX\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eNGK stock number: \u003cstrong\u003e7164\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eIridium center electrode for stable spark and long service performance.\u003c\/li\u003e\n\u003cli\u003eProjected-tip design.\u003c\/li\u003e\n\u003cli\u003eResistor-style spark plug.\u003c\/li\u003e\n\u003cli\u003eSolid terminal configuration.\u003c\/li\u003e\n\u003cli\u003eThread diameter: \u003cstrong\u003e14 mm \/ M14 x 1.25\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eThread reach: \u003cstrong\u003e17.5 mm listed \/ 18 mm class\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eHex size: \u003cstrong\u003e5\/8 in. \/ 16 mm\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eSeat style: \u003cstrong\u003etapered seat\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eHeat range: \u003cstrong\u003e5\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eCommon preset gap reference: \u003cstrong\u003e0.059 in. \/ 1.5 mm\u003c\/strong\u003e.\u003c\/li\u003e\n\u003cli\u003eUsed where the application chart calls for the TR55IX plug profile.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cstrong\u003eApplication Compatibility\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eCommon application context includes select engines that call for the \u003cstrong\u003eNGK TR55IX \/ 7164\u003c\/strong\u003e plug profile, including:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eSelect \u003cstrong\u003eGeneral Motors LS-based V8\u003c\/strong\u003e applications where specified\u003c\/li\u003e\n\u003cli\u003eSelect \u003cstrong\u003e4.8L, 5.3L, 5.7L LS1\/LS6, 6.0L, and 6.2L GM V8\u003c\/strong\u003e applications where the plug chart calls for TR55IX\u003c\/li\u003e\n\u003cli\u003eSelect \u003cstrong\u003eFord 4.6L and 5.4L V8\u003c\/strong\u003e applications where specified\u003c\/li\u003e\n\u003cli\u003eSelect EFI marine inboard and sterndrive engine applications where the engine manufacturer's plug chart confirms TR55IX\u003c\/li\u003e\n\u003cli\u003eSelect performance, street, and marine applications using the correct TR-series tapered-seat plug geometry\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eUse this spark plug only where the manufacturer's spark plug chart specifically calls for \u003cstrong\u003eTR55IX\u003c\/strong\u003e, \u003cstrong\u003e7164\u003c\/strong\u003e, or an approved equivalent.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eFitment Notice\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eConfirm fitment by exact year, make, model, engine, service manual, ignition system, and factory spark plug chart before ordering. Spark plugs with similar NGK part numbers can still differ in reach, gap, heat range, seat style, projected-tip design, terminal type, and electrode design. Installing the wrong plug can cause hard starting, misfire, poor idle, thread damage, overheating, piston contact, or ignition-system issues.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eWhen This Part Needs Replacement\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eReplace spark plugs during scheduled tune-up service or whenever plugs are fouled, worn, fuel-soaked, oil-contaminated, cracked, corroded, damaged, or causing hard starting, rough idle, hesitation, misfire, reduced throttle response, or poor fuel economy. Marine engines, tow vehicles, and high-load applications should have spark plugs inspected regularly because ignition problems often show up first under acceleration or sustained load.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eInstallation Notes\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eCheck the plug number and required gap against the engine's service chart before installation. The TR55IX uses a \u003cstrong\u003etapered seat\u003c\/strong\u003e, so it does not use a separate sealing washer. Install into clean, undamaged cylinder head threads and tighten to the engine manufacturer's torque specification.\u003c\/p\u003e\n\u003cp\u003eAvoid adding anti-seize unless the engine or plug manufacturer specifically calls for it, as lubricant changes thread friction and can lead to over-tightening. If gap adjustment is required, adjust only the ground strap and avoid prying against the fine iridium center electrode.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eAlternate\/Superseded Part Numbers\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eNGK TR55IX\u003c\/strong\u003e — spark plug part number\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNGK 7164\u003c\/strong\u003e — NGK stock number\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTR55IX Iridium IX\u003c\/strong\u003e — product style reference\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTR5\u003c\/strong\u003e — related NGK V-Power plug profile with a different electrode design and typical preset gap; verify before substitution\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTR55\u003c\/strong\u003e — related NGK plug profile with different construction; verify by application chart before substitution\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cstrong\u003eParts Desk Insight\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe \u003cstrong\u003eTR55IX\u003c\/strong\u003e should not be selected only because an engine uses a GM LS, Ford V8, or marine V8 platform. The correct plug depends on the engine's required gap, ignition system, cylinder head thread style, heat range, and service chart. The wide \u003cstrong\u003e0.059 in.\u003c\/strong\u003e gap reference is common for TR55-style applications, but some engines require a narrower gap, especially after ignition updates, forced induction, or marine service changes.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eShipping:\u003c\/strong\u003e Ships same or next day for fast Canada wide shipping. ⚓\u003c\/p\u003e","brand":"WEST","offers":[{"title":"Default Title","offer_id":43564191809572,"sku":"NGK-TR55IX","price":31.42,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/82646e23-7444-452c-bb78-6e22065469ee.png?v=1781200880","url":"https:\/\/marisolmarine.com\/products\/west-1151","provider":"Marisol Marine Company","version":"1.0","type":"link"}