# NGK Spark Plugs: MerCruiser, Mercury & Chrysler Inboards ## NGK Spark Plugs: MerCruiser, Mercury & Chrysler Inboards 183 spark plug applications from NGK's marine catalogue, for the engines we supply parts for. Each line gives the plug NGK specifies, the iridium upgrade where one exists, and the electrode gap. **Check the gap before you fit.** Plugs are not always gapped correctly out of the box, and the wrong gap causes misfire and hard starting. Where a resistor plug is specified, fit a resistor plug — a non-resistor substitute can interfere with a tacho, sounder or engine electronics. - [MerCruiser](#mercruiser) - [Mercury](#mercury) - [Chrysler](#chrysler) - [Ford](#ford) - [Chevrolet (marine conversions)](#chevrolet-marine-conversions) - [Toyota](#toyota) ### MerCruiser 123 applications Model Engine / details NGK plug Iridium upgrade Gap DIESEL 530D-TA · Diesel · 89→93 Y-909R DIESEL 636D-TA · Diesel · 89→93 Y-909R DIESEL D183 TURBO AC · Diesel · 90→93 Y-909R DIESEL D219 TURBO AC · Diesel · 90→93 Y-909R DIESEL 3.0 · D3.0L · Diesel · 94→97 Y-909R DIESEL 3.6 · D3.6L · Diesel · 94→97 Y-909R DIESEL 3.6 · D3.6L · Diesel · 97→97 Y-909R DIESEL 4.2 · D4.2L/220 · Diesel · 94→99 Y-909R INBOARD 4-CYL. 470 BPR6FS 0.9 mm INBOARD 8-CYL. FORD 233 Dia. 14 mm plug BPR6FS 0.8 mm SMALL BLOCK 255 BR6FS 0.9 mm INBOARD 8-CYL. GM 325 V: To: 2 762 441 BUE 1.3 mm BIG BLOCK 325 V: 2 762 442 on R5673-8 0.9 mm BIG BLOCK 330, 340 BR6FS 0.9 mm BIG BLOCK 350 R5673-8 0.9 mm BIG BLOCK 390 BPR8ES BPR8EIX 0.9 mm BIG BLOCK 400 Jet BR6FS 0.9 mm BIG BLOCK 454 EFI MPI BR6FS 1.0 mm BIG BLOCK 454 Mag MPI V: 0L 002 200 on BR6FS 0.9 mm BIG BLOCK 454 MPI BR6FS 1.0 mm BIG BLOCK 7.4 · 7.4L Incl. EFI 11.2 mm reach plugs BR6FS 1.0 mm BIG BLOCK 7.4 · 7.4L MPI BR6FS 1.0 mm BIG BLOCK 7.4 · 7.4L MPI BPR6EFS BPR6EFIX-10 1.1 mm BIG BLOCK 8.1 · 8.1S HO, Horizon · 00→06 PTR5D-13 TR5AI-13 1.5 mm BIG BLOCK 8.2 · 8.2L (Incl. MPI) BR6FS 1.0 mm INBOARD 8-CYL. GM 198 BR5FS 0.9 mm SMALL BLOCK 225 B7S 0.8 mm SMALL BLOCK 228, 230 BR5FS 0.9 mm SMALL BLOCK 250 B7S 1.0 mm SMALL BLOCK 255, 260 BR6FS 0.9 mm SMALL BLOCK 270 Gasket seat plugs B7S 0.9 mm SMALL BLOCK 270 Taper seat plugs R5673-8 0.9 mm SMALL BLOCK 350 MAG, EFI, MPI, SKI · 87→97 BR6FS 1.0 mm SMALL BLOCK 350 MAG MPI, Gen+ · 98→00 BPR6EFS BPR6EFIX-10 1.1 mm SMALL BLOCK 350 MAG MPI, Gen+ · 00→06 PZTR5A-15 1.5 mm SMALL BLOCK 454 EFI (Incl. MPI) BR6FS 1.0 mm SMALL BLOCK 5.0 · 5.0L BR5FS 0.9 mm SMALL BLOCK 5.0 · 5.0L MPI BR6FS 1.0 mm SMALL BLOCK 5.7 · 5.7L, Comp BR6FS 1.0 mm SMALL BLOCK 5.7 · 5.7L Comp Gen+, EFI BPR6EFS BPR6EFIX-10 1.1 mm SMALL BLOCK 5.7 · Black Scorpion 5.7L · 00→06 BPR6EFS BPR6EFIX-10 1.1 mm SMALL BLOCK 5.7 · Black Scorpion 5.7L · 00→06 PTR5D-13 TR5AI-13 1.5 mm SMALL BLOCK 6.2 · Black Scorpion MX 6.2 · 00→06 BPR5EFS PTR5D-10 0.9 mm SMALL BLOCK 6.2 · Black Scorpion MX 6.2 · 00→06 PTR5D-13 TR5AI-13 1.5 mm SMALL BLOCK 6.2 · MX 6.2 MPI · 00→06 BPR6EFS BPR6EFIX-10 1.1 mm SMALL BLOCK 6.2 · MX 6.2 MPI · 00→06 PTR5D-13 TR5AI-13 1.5 mm SMALL BLOCK 6.2 · MX 6.2 MPI Horizon · 00→06 PTR5D-13 TR5AI-13 1.5 mm SMALL BLOCK Scorpion 377 BPR6EFS BPR6EFIX-10 1.1 mm STERN DRIVE 4-CYL. 2.5 · 2.5L · 153 cu.inch BR6FS 0.9 mm GM 3.0 · 3.0L · 181 cu.inch · 82→94 BR6FS 0.9 mm GM 3.0 · 3.0L · 181 cu.inch · 98→ BPR6EFS BPR6EFIX-10 0.9 mm GM 3.0 · 3.0LX · 90→95 BR6FS 0.9 mm GM 3.0 · 3.0LX · 90→97 BPR6EFS BPR6EFIX-10 0.9 mm GM 110 BR6ES 0.9 mm GM 120 · 64→86 BR6FS 0.9 mm GM 140 · 68→86 BR6FS 0.9 mm STERN DRIVE 4-CYL. 470, 485, 488 · 224 cu.inch · 76→84 BPR6FS 0.9 mm STERN DRIVE 4-CYL. 165, 170, 180, 190 · 224 cu.inch · 85→87 BPR6FS 0.9 mm STERN DRIVE 4-CYL. 3.7 · 3.7L, 3.7LX · 224 cu.inch · 88→89 BPR6FS 0.9 mm STERN DRIVE 4-CYL. 60 12.7 mm reach plugs BR6HS BR6HIX 0.6 mm RENAULT 80 19 mm reach plugs BPR6ES BPR6EIX 0.6 mm RENAULT 90 19 mm reach plugs BPR6ES BPR6EIX 0.8 mm STERN DRIVE 6-CYL. 140, 150, 160 BR6ES 0.9 mm CHEVROLET L-6 165 V: To: 2 771 483 BR6ES 0.9 mm CHEVROLET L-6 165 V: 2 771 484 on BR5FS 0.9 mm CHEVROLET L-6 200 BR6ES 0.9 mm STERN DRIVE 6-CYL. 4.3 · 4.3L, 4.3LX · 88→96 BR6FS 1.0 mm STERN DRIVE 6-CYL. 4.3 · 4.3L, 4.3LX, 4.3LXH, EFI, Gen+ · (Excl. MPI) · 96→98 BPR6EFS BPR6EFIX-10 1.1 mm STERN DRIVE 6-CYL. 4.3 · 4.3L MPI Gen+ · 98→ PTR5D-13 TR5AI-13 1.5 mm STERN DRIVE 6-CYL. 175, 185, 205 · 229 cu.inch · 85→87 BR6FS 0.9 mm STERN DRIVE 6-CYL. 262 Mag EFI Gen+ BPR6EFS BPR6EFIX-10 1.1 mm STERN DRIVE 8-CYL. 325 V: To: 2 761 141 BUE 1.3 mm CHEVROLET 325 V: 3 043 030 on R5673-8 0.9 mm BIG BLOCK 330, B-W, 370 BR6FS 0.9 mm BIG BLOCK 390 BPR8ES BPR8EIX 0.9 mm STERN DRIVE 8-CYL. 400, 420, 440, Incl. Cyclone BR6FS 0.9 mm CHEVROLET 454 MAG Alpha, Bravo, EFI, MPI, · 88→01 BR6FS 0.9 mm CHEVROLET 460 Cyclone, 475 Turbo R5673-8 0.9 mm CHEVROLET 496 Mag (Incl. HO) PTR5D-13 TR5AI-13 1.5 mm CHEVROLET 502 Mag, EFI, MPI · 90→01 BR6FS 1.0 mm CHEVROLET 7.4 · 7.4L, 7.4LX, Alpha, Bravo, EFI, MPI, TR · 88→97 BR6FS 0.9 mm CHEVROLET 7.4 · 7.4L MPI (L29) · 98→00 BPR6EFS BPR6EFIX-10 1.1 mm CHEVROLET HP425, 450, 465 BR6FS 0.9 mm CHEVROLET HP500 · 502 cu.inch Incl. EFI (Excl. 540 cu.inch) BR6FS 1.0 mm CHEVROLET HP500 · 540 cu.inch R5673-8 0.9 mm CHEVROLET HP525 (Excl. SC) · 502 cu.inch BR6ES 0.9 mm CHEVROLET HP525 SC R5673-8 0.9 mm CHEVROLET HP575 (Incl. SCi) R5673-8 0.9 mm CHEVROLET HP600 SCi (Excl. SC) BR6ES 0.9 mm CHEVROLET HP600 SC R5673-8 0.9 mm CHEVROLET HP700 SCi BR6ES 0.9 mm CHEVROLET HP800 SC R5673-8 0.9 mm CHEVROLET HP850 SCi BR9ECS 0.8 mm CHEVROLET HP900 SC (Excl. Dry Sump) R7434-9 0.7 mm CHEVROLET HP900 SC Dry Sump R7434-9 0.6 mm CHEVROLET HP1075 Sci Dry Sump BR9ECS 0.8 mm STERN DRIVE 8-CYL. 5.0 · 5.0L, 5.0LX · 88→95 BR6FS 0.9 mm STERN DRIVE 8-CYL. 5.0 · 5.0L, EFI, Gen+ · 98→01 BPR6EFS BPR6EFIX-10 1.1 mm STERN DRIVE 8-CYL. 5.0 · 5.0L MPI · 02→ PTR5D-13 TR5AI-13 1.5 mm STERN DRIVE 8-CYL. 5.7 · 5.7L, 5.7LX (Incl. EFI) · 88→97 BR6FS 1.0 mm STERN DRIVE 8-CYL. 5.7 · 5.7L, 5.7LX, Gen+ (Incl. EFI) · 98→01 BPR6EFS BPR6EFIX-10 1.1 mm STERN DRIVE 8-CYL. 225 V: To: 2 278 646 B7S 0.9 mm STERN DRIVE 8-CYL. 228, 230 BR5FS 0.9 mm STERN DRIVE 8-CYL. 250 V: To: 2 639 854 B7S 0.8 mm STERN DRIVE 8-CYL. 250 V: 4 768 000 on BR6FS 0.9 mm STERN DRIVE 8-CYL. 255, 260 BR6FS 0.9 mm STERN DRIVE 8-CYL. 270 Gasket seat plugs B7S 0.8 mm STERN DRIVE 8-CYL. 270 Taper seat plugs R5673-8 0.9 mm STERN DRIVE 8-CYL. 280 BR6FS 0.9 mm STERN DRIVE 8-CYL. 300 Tempest BR6FS 0.9 mm STERN DRIVE 8-CYL. 320 EFI BR6FS 0.9 mm STERN DRIVE 8-CYL. 350 Mag EFI, MPI V: To: 0F 602 199 BR6FS 1.0 mm STERN DRIVE 8-CYL. 350 Mag EFI, MPI Gen+, Horizon BPR6EFS BPR6EFIX-10 1.1 mm STERN DRIVE 8-CYL. 350 Mag MPI Gen+ Horizon BPR5EFS PTR5D-10 0.9 mm STERN DRIVE 8-CYL. 350 Mag MPI Gen+ Horizon PTR5D-13 TR5AI-13 1.5 mm STERN DRIVE 8-CYL. 898, 200 BR5FS 0.9 mm STERN DRIVE 8-CYL. 6.2 · MX 6.2 MPI V: To: 0M 320 613 BPR6EFS BPR6EFIX-10 1.1 mm STERN DRIVE 8-CYL. 6.2 · MX 6.2 MPI, Horizon V: 0M 320 614 on PTR5D-13 TR5AI-13 1.5 mm STERN DRIVE 8-CYL. Scorpion 377 V: 0L 416 146 on BPR6EFS BPR6EFIX-10 1.1 mm STERN DRIVE 8-CYL. 225, 233 Dia. 14 mm plug · 06→ BPR6FS 0.8 mm FORD 255 V: To: 4 175 498 Dia. 14 mm plug BR6FS 0.8 mm SMALL BLOCK 255 V: 4 175 499 on Dia. 14 mm plug BPR6FS 0.8 mm SMALL BLOCK 888 V: 4 169 597 on Dia. 14 mm plug BPR6FS 0.8 mm Parts for these engines: [MerCruiser parts](/collections/quicksilver-marine-parts-oils-service-kits-engine-components). ### Mercury 9 applications Model Engine / details NGK plug Iridium upgrade Gap 90 HP Sport Jet · 94→ BZ7HS-10 1.0 mm 95 HP Sportjet 95XR · 96→97 BZ7HS-10 1.0 mm 120 HP Sportjet 120 (Excl. XR) · 95→ BZ7HS-10 1.0 mm 120 HP Sportjet 120XR · 96→99 BZ7HS-10 0.8 mm 175 HP Sportjet 175XR · 97→06 BUZ8H 1.5 mm 200 HP Sport Jet · 06→ IZFR5G 0.8 mm 210 HP M2 Sport Jet · 00→06 BUZ8H 1.5 mm 240 HP M2 Sport Jet · 00→06 BPZ8HS-10 1.0 mm 250 HP M2 Sport Jet · 06→ IZFR5G 0.8 mm Parts for these engines: [Mercury parts](/collections/quicksilver-marine-parts-oils-service-kits-engine-components). ### Chrysler 25 applications Model Engine / details NGK plug Iridium upgrade Gap 4-CYL. M91D, M91F BP6ES BPR6EIX 0.9 mm 4-CYL. M122A, M122B B7HS BR7HIX 0.9 mm 6-CYL. B46-4, B46S-3 BR6S 0.9 mm 6-CYL. M46-3 BR6S 0.9 mm 6-CYL. M47-3, M47-4, M47S-3 BR6S 0.9 mm 6-CYL. M170 BR6ES 0.9 mm 6-CYL. M183B B7HS BR7HIX 0.9 mm 6-CYL. M225A BR6ES 0.9 mm 6-CYL. M225D · 28 hp · →74 BR6ES 0.9 mm 6-CYL. M225D · 30 hp · 75→79 BPR6FS 0.9 mm 6-CYL. M225D · 35 hp BR6ES 0.9 mm 6-CYL. M225GD BR6ES 0.9 mm 6-CYL. M265, M265A BR6S 0.9 mm 8-CYL. LM318A, LM318AC BPR6ES BPR6EIX 0.9 mm 8-CYL. LM318B, LM318BC, LM318BJ, BPR6ES BPR6EIX 0.9 mm 8-CYL. LM318D BPR6ES BPR6EIX 0.9 mm 8-CYL. LM340B, LM340BJ, LM340BT, LM340BV BPR6ES BPR6EIX 0.9 mm 8-CYL. M44, M44-3 BR6S 0.9 mm 8-CYL. M45, M45-3 BR6ES 0.9 mm 8-CYL. M45S, M45-S3, M45-SP3 BR6ES 0.9 mm 8-CYL. M81 BR6ES 0.9 mm 8-CYL. M273A, M273B, M273BT BPR6ES BPR6EIX 0.9 mm 8-CYL. M360A, M360B, M360BC, M360BJ, BPR6ES BPR6EIX 0.9 mm 8-CYL. M413E BR6ES 0.9 mm 8-CYL. M460B BPR5FS 0.9 mm ### Ford 10 applications Model Engine / details NGK plug Iridium upgrade Gap 67 cu.inch BPR5E BPR5EIX 0.9 mm 98 cu.inch BPR5E BPR5EIX 0.9 mm 104 cu.inch BPR4ES GR4IX 0.7 mm 158 cu.inch BR6ES 0.9 mm 172 cu.inch B-6L 0.7 mm 201 cu.inch BR6ES 0.9 mm 427 cu.inch 302, 351W Dia. 18 mm plug · →74 APR5FS 0.9 mm 427 cu.inch Dia. 14 mm plug · 75→89 BPR5FS 0.7 mm 429 cu.inch 75→89 BPR5FS 0.7 mm 460 cu.inch 302, 351W Dia. 14 mm plug · 75→89 BPR5FS 0.8 mm ### Chevrolet (marine conversions) 13 applications Model Engine / details NGK plug Iridium upgrade Gap 6-CYL. 194 cu.inch · 62→69 BPR5ES BPR5EIX 0.9 mm 6-CYL. 230 cu.inch · 62→69 BPR5ES BPR5EIX 0.9 mm 6-CYL. 230 cu.inch · 70→ BPR4FS-11 1.1 mm 6-CYL. 250 cu.inch · 62→69 BPR5ES BPR5EIX 0.9 mm 6-CYL. 250 cu.inch · 79→84 BPR4FS-11 1.1 mm 6-CYL. 292 cu.inch · 63→69 BPR4FS-11 1.1 mm 6-CYL. 292 cu.inch · 70→78 BPR5FS 0.7 mm 8-CYL. 307 cu.inch · 71→73 BPR5FS 0.7 mm 8-CYL. 350 cu.inch · 71→90 BPR4FS-11 1.1 mm 8-CYL. 400 cu.inch · 71→90 BPR4FS-11 1.1 mm 8-CYL. 427 cu.inch · 71→72 BPR6FS 0.7 mm 8-CYL. 427 cu.inch · 73→90 BPR4FS-11 1.1 mm 8-CYL. 454 cu.inch · 79→90 BPR5FS 0.8 mm ### Toyota 3 applications Model Engine / details NGK plug Iridium upgrade Gap EPIC 21, 22 IFR6T11 1.1 mm EPIC 4.0 · VT 300i · 8-Cyl. PFR5G-11 BKR5EIX-11 1.1 mm S22, X22 S22, X22 IFR6T11 1.1 mm ### Reading the plug codes An NGK code describes the plug's construction. The digit in the middle is the heat rating — a **higher number is a colder plug**, which is the opposite of most other brands. An **R** after the first letters means a resistor plug. Codes ending **IX** are the Iridium IX range, a direct upgrade with a finer centre electrode. A **Y-** prefix is a diesel glow plug, not a spark plug, and has no gap. Do not substitute a hotter or colder plug to cure a running problem. A plug reading the wrong colour is telling you about the fuel, ignition or oil — changing heat range hides it rather than fixing it. ### Other engines - [Mercury](/pages/ngk-spark-plugs-mercury-outboards) - [Mariner / Force](/pages/ngk-spark-plugs-mariner-force-outboards) - [Yamaha](/pages/ngk-spark-plugs-yamaha-outboards) - [Suzuki](/pages/ngk-spark-plugs-suzuki-outboards) - [Johnson](/pages/ngk-spark-plugs-johnson-outboards) - [Evinrude / OMC](/pages/ngk-spark-plugs-evinrude-omc-outboards) - [Tohatsu / Nissan](/pages/ngk-spark-plugs-tohatsu-nissan-outboards) - [Honda / Volvo Penta / others](/pages/ngk-spark-plugs-honda-volvo-penta-outboards) - [Other inboards](/pages/ngk-spark-plugs-inboard-sterndrive) - [PWC & jet ski](/pages/ngk-spark-plugs-pwc-jet-ski) ### Not sure which plug you need? Model families ran across several specifications and the year or serial usually decides which line applies. Ring [0412 532 984](tel:+61412532984) with your engine and serial number and we will confirm the plug, the gap and how many you need. Our other workshop charts are on the [reference charts page](/pages/resources), and the how-and-why lives in our [boat maintenance guides](/blogs/guides). Applications compiled from NGK's published marine application guide and reproduced here as reference data. NGK's own guide is the authority; always confirm against your engine's manual. Listings do not apply to racing or modified engines. --- > Source: [Sawley's Auto and Marine](https://www.sawleysautoandmarine.com.au/pages/ngk-spark-plugs-mercruiser-inboard)