{"product_id":"ngk-5599-laser-iridium-spark-plug-itr4a15-4-pack","title":"NGK ITR4A15 Laser Iridium Spark Plug - 5599","description":"\u003cp\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0056\/9429\/2079\/files\/ngk_logo_1.png?v=1780608867\" alt=\"\"\u003e\u003c\/p\u003e\n\u003ch2\u003eNGK ITR4A15 Laser Iridium Spark Plug – 5599\u003c\/h2\u003e\n\u003cp\u003eThe NGK ITR4A15 Laser Iridium Spark Plug, stock number 5599, is a premium ignition replacement for select MerCruiser MPI inboard and sterndrive engines. Designed for long service life and consistent firing performance, it combines a fine-wire iridium center electrode with a platinum-tipped ground electrode to provide dependable starting, smooth acceleration, and efficient combustion.\u003c\/p\u003e\n\u003cp\u003eMarine engines regularly operate under sustained loads that place additional demands on the ignition system. The ITR4A15 is built to maintain a stable spark through repeated heat cycles while resisting electrode wear and gap erosion. NGK's copper-core construction also helps transfer heat away from the firing tip, while the resistor design reduces electrical interference with onboard electronics.\u003c\/p\u003e\n\u003cp\u003eReplacing worn plugs can help correct hard starting, rough idle, hesitation, intermittent misfires, and declining engine performance. For compatible MerCruiser power packages, NGK 5599 is an excellent choice for scheduled maintenance or a complete ignition tune-up.\u003c\/p\u003e\n\u003ch3\u003eSpark Plug Specifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eManufacturer: NGK\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003ePart Number: ITR4A15\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eNGK Stock Number: 5599\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSeries: Laser Iridium\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eCenter Electrode: Fine-wire iridium\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eGround Electrode: Platinum-tipped\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eCenter Electrode Core: Copper\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eHeat Range: 4\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eThread Size: M14 x 1.25\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eThread Reach: 17.5 mm\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eHex Size: 16 mm \/ 5\/8\"\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSeat Type: Tapered\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSpark Gap: 1.5 mm \/ .060\"\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eResistor Type: Yes\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSold Individually\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCommon MerCruiser Engine Applications\u003c\/h3\u003e\n\u003cp\u003eThe NGK ITR4A15 \/ 5599 is used in select MerCruiser MPI and Tow Sports engines, including:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eMerCruiser 4.3L MPI V6\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMerCruiser 4.3L MPI EC\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMerCruiser 5.0L MPI V8\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMerCruiser 5.0L MPI EC\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMerCruiser 5.7L MPI\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMerCruiser 5.7L MPI MIE\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMerCruiser 5.7L MPI Tow Sports\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMerCruiser 5.7L MPI Tow Sports EC\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMerCruiser 350 MAG MPI\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMerCruiser 350 MAG MPI MIE\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMerCruiser 350 MAG MPI Horizon\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMerCruiser 377 MAG\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMerCruiser 377 MAG EC\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMerCruiser Black Scorpion Ski\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMerCruiser Black Scorpion Ski Gen+\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSelect MerCruiser 6.2L MPI applications\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCommon Inboard \u0026amp; Tow Boat Applications\u003c\/h3\u003e\n\u003cp\u003eMerCruiser Tow Sports and Black Scorpion engines were installed in a variety of tournament ski, wake, and performance boats. Depending on model year and original engine package, potential applications include:\u003c\/p\u003e\n\u003ch4\u003eCenturion\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eCenturion Avalanche\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eCenturion Elite V\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eCenturion Enzo SV230\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eCenturion Enzo SV240\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSelect Centurion Air Warrior models\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eSupreme\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eSupreme V208\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSupreme V220\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSupreme V226\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSelect Supreme wake boat models\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eTige\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eTige 20V\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eTige 21i\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eTige 22V\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eTige 22Ve\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eTige 24V\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eTige 24Ve\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eSanger\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eSanger V210\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSanger V215\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSanger V230\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSanger DXII\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSelect Sanger V-drive models\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eCommon MerCruiser Sterndrive Boat Applications\u003c\/h3\u003e\n\u003cp\u003eThe ITR4A15 is also used with compatible MerCruiser MPI sterndrive engines installed in recreational boats such as:\u003c\/p\u003e\n\u003ch4\u003eSea Ray\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eSea Ray 185 Sport\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSea Ray 205 Sport\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSea Ray 210 Select\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSea Ray 220 Sundeck\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSea Ray 240 Sundeck\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSelect Sea Ray Sundancer models\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eChaparral\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eChaparral 204 SSi\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eChaparral 216 SSi\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eChaparral 226 SSi\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eChaparral 236 SSi\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eChaparral 246 SSi\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSelect Chaparral Signature models\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCrownline\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eCrownline 202 BR\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eCrownline 220 EX\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eCrownline 240 EX\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eCrownline 250 CR\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eCrownline 270 CR\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eFour Winns\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eFour Winns H200\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eFour Winns H210\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eFour Winns H220\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eFour Winns H240\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSelect Four Winns Vista models\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eRinker\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eRinker Captiva 192\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eRinker Captiva 212\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eRinker Captiva 246\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eRinker 260 Express Cruiser\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSelect Rinker Fiesta Vee models\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eAdditional applications may include compatible MerCruiser-powered boats from Cobalt, Regal, Monterey, Stingray, Glastron, Larson, Formula, Baja, and other recreational boat manufacturers.\u003c\/p\u003e\n\u003ch3\u003eMercury \/ MerCruiser Cross References\u003c\/h3\u003e\n\u003cp\u003eThe NGK ITR4A15 \/ 5599 is associated with Mercury and MerCruiser replacement numbers including:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eMercury \/ MerCruiser 8M0204739\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMercury \/ MerCruiser 8M2018369\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMercury \/ MerCruiser 884019\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eMercury \/ MerCruiser 884019001\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eNGK ITR4A15\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eNGK 5599\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003eGenuine NGK ITR4A15 Laser Iridium spark plug\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eNGK stock number 5599\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eDesigned for select MerCruiser MPI marine engines\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eFine-wire iridium center electrode provides excellent durability\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003ePlatinum ground electrode helps minimize gap erosion\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eCopper core promotes efficient heat dissipation\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eResistor construction helps reduce electrical interference\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eSupports dependable starting and smooth acceleration\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eHelps maintain efficient combustion under heavy engine loads\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003eIdeal for seasonal service and preventative maintenance\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003ePremium Ignition Performance for MerCruiser MPI Engines\u003c\/h3\u003e\n\u003cp\u003eMerCruiser MPI engines depend on precise fuel and ignition control to deliver smooth power throughout the operating range. A worn spark plug can reduce ignition efficiency and contribute to misfires, difficult starting, hesitation, or reduced performance. The NGK ITR4A15 Laser Iridium design provides the durability and firing consistency needed for these electronically controlled marine engines.\u003c\/p\u003e\n\u003cp\u003eWhether you're servicing a MerCruiser 4.3L MPI, 5.0L MPI, 5.7L MPI, 350 MAG MPI, 377 MAG, or Black Scorpion-powered boat, the NGK ITR4A15 Laser Iridium Spark Plug – 5599 provides a proven replacement for maintaining reliable performance on the water.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFitment Note:\u003c\/strong\u003e MerCruiser used different spark plugs within the same engine displacement depending on model year, ignition system, emissions configuration, and serial-number range. Boat manufacturers also offered multiple engine packages in the same hull. Always verify \u003cstrong\u003eNGK ITR4A15 \/ stock #5599\u003c\/strong\u003e against your MerCruiser engine model, serial number, service manual, or original Mercury part number before ordering.\u003c\/p\u003e","brand":"Land 'N' Sea","offers":[{"title":"Default Title","offer_id":50255019802881,"sku":"41-ITR4A15","price":16.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0056\/9429\/2079\/files\/8c03bee608eb8672b9ecd69fa5ed4649.jpg?v=1788029461","url":"https:\/\/inboardpartshq.com\/products\/ngk-5599-laser-iridium-spark-plug-itr4a15-4-pack","provider":"Inboard Parts HQ","version":"1.0","type":"link"}