Mercury V8 300

Measuring Spark Plug Wire Resistance
• Resistance values vary by spark plug location (refer to specification table)
• Measure resistance from end to end (coil boot to plug boot)
• Never penetrate wire insulation with meter probes
• Digital meters are more accurate than analog meters
• Different meters may show different resistance values
• Any value within 10% of the specification should be considered acceptable
Spark Plug Wire Resistance ‑ V6 Models
Cylinder Length (see NOTE) Resistance
1 18.4 cm (7.25 in.) 1,613–7,833 Ω
2 21.6 cm (8.5 in.) 1,800–8,667 Ω
3 17.8 cm (7.0 in.) 1,575–7,667 Ω
4 59.7 cm (23.5 in.) 4,050–18,667 Ω
5 48.26 cm (19.0 in.) 3,375–15,667 Ω
6 43.2 cm (17.0 in.) 3,075–14,333 Ω
NOTE: The length of each spark plug wire is measured between the coil terminal (center of the coil boot) and the plug boot
(center of the plug boot). Each stated length is plus or minus 0.6 cm (0.25 in.).
Spark Plug Wire Resistance ‑ V8 Models
Cylinder
Length (see NOTE) Resistance
1 35.56 cm (14.0 in.) 2,625–12,333 Ω
2 27.3 cm (10.75 in.) 2,138–10,167 Ω
3 35.56 cm (14.0 in.) 2,625–12,333 Ω
4 66.0 cm (26.0 in.) 4,425–20,333 Ω
5 66.0 cm (26.0 in.) 4,425–20,333 Ω
6 24.1 cm (9.5 in.) 1,950–9,333 Ω
7 48.26 cm (19.0 in.) 3,375–15,667 Ω
8 41.3 cm (16.25 in.) 2,963–13,833 Ω
NOTE: The length of each spark plug wire is measured between the coil terminal (center of the coil boot) and the plug boot
(center of the plug boot). Each stated length is plus or minus 0.6 cm (0.25 in.).
Ignition
Page 6A-8 © 2018 Mercury Marine 90-8M0146617 eng JULY 2018