Suzuki specifies a standard NGK spark plug for every DF outboard by NGK part number, and the number changes with the model year: the DF9.9B/15A/20A and DF25A/30A moved from CPR6EA-9 to MR6K-9, the DF115/140 B and BG models use LKR6E instead of the A models' BKR6E, and the supercharged DF350A uses an iridium ILZKR7D8. The chart below is taken from Suzuki's 2025 4-stroke maintenance manual.
Use only resistor-type plugs. Suzuki's schedule is to inspect the plugs at every 100 hours or 12 months and replace them when the electrodes or insulator are worn or damaged; there is no fixed replacement hour count in the owner's manuals. Seat the plug by hand, then tighten to the torque shown. Over-tightening damages the aluminum threads in the head.
Suzuki spark plug chart by model
| Model (years) | NGK plug | Qty | Gap | Torque |
|---|---|---|---|---|
| DF2.5 (2006+) | NGK CR6HSA | 1 | 0.6–0.7 mm | 11 N·m |
| DF4 / DF5 / DF6 (2002–2010) | NGK BPR6ES | 1 | 0.7–0.8 mm | 28 N·m |
| DF4 / DF5 / DF6 (2011–2015), DF4A / DF5A / DF6A (2017+) | NGK CPR6EA-9 | 1 | 0.8–0.9 mm | 11 N·m |
| DF8A / DF9.9A (2010+) | NGK CR6E | 2 | 0.7–0.8 mm | 11 N·m |
| DF9.9 / DF15 (2005–2010, carbureted) | NGK BKR6E | 2 | 0.7–0.8 mm | 27 N·m |
| DF15 (2011–2012) | NGK CPR6EA-9 | 2 | 0.8–0.9 mm | 11 N·m |
| DF9.9B / DF15A / DF20A (2013–2017) | NGK CPR6EA-9 | 2 | 0.8–0.9 mm | 11 N·m |
| DF9.9B / DF15A / DF20A (2018+) | NGK MR6K-9 | 2 | 0.8–0.9 mm | 11 N·m |
| DF25 V-twin (2006–2014) | NGK BKR6E | 2 | 0.7–0.8 mm | 28 N·m |
| DF25 / DF30 3-cyl. (2006–2010) | NGK DCPR6E | 3 | 0.8–0.9 mm | 18 N·m |
| DF25A / DF30A (2015–2018) | NGK CPR6EA-9 | 3 | 0.8–0.9 mm | 11 N·m |
| DF25A / DF30A (2019+) | NGK MR6K-9 | 3 | 0.8–0.9 mm | 11 N·m |
| DF40 / DF50 (1999–2010) | NGK DCPR6E | 3 | 0.8–0.9 mm | 18 N·m |
| DF40A / DF50A / DF60A / DF50AV / DF60AV (2010+) | NGK DCPR6E | 3 | 0.8–0.9 mm | 17 N·m |
| DF60 / DF70 (1998–2009) | NGK BPR6ES | 4 | 0.7–0.8 mm | 28 N·m |
| DF70A / DF80A / DF90A / DF100B (2009+) | NGK DCPR6E | 4 | 0.8–0.9 mm | 18 N·m |
| DF90 / DF100 / DF115 / DF140 (2001–2012) | NGK BKR6E | 4 | 0.7–0.8 mm | 28 N·m |
| DF100A / DF115A / DF140A (2013+) | NGK BKR6E | 4 | 0.7–0.8 mm | 28 N·m |
| DF100C / DF115B / DF140B (2022+), DF115BG / DF140BG (2021+) | NGK LKR6E | 4 | 0.8–0.9 mm | 17 N·m |
| DF150 / DF175 (2006+), DF150TG / DF175TG | NGK BKR6E | 4 | 0.7–0.8 mm | 28 N·m (27 on TG) |
| DF150A / DF175A (2019+), DF150AP / DF175AP (2017+), DF200A / DF200AP (2015+) | NGK LKR6E | 4 | 0.8–0.9 mm | 17 N·m |
| DF200 / DF225 / DF250 V6 (2004+), DF300 (2007–2011), DF250AP / DF300AP (2012+) | NGK BKR6E | 6 | 0.7–0.8 mm | 28 N·m |
| DF300B / DF325A / DF350A (2018+) | NGK ILZKR7D8 | 6 | 0.7–0.8 mm | 17 N·m |
Boat Max Online is an authorized Suzuki Marine dealer; the plugs we sell are genuine NGK through authorized distribution. Free shipping on orders over $149 to the lower 48 states.
Source: Suzuki 4-Stroke Outboard Maintenance Manual, Spark Plug Data (Feb 2025).