Spark Plug Inspection And Replacement - Mercury 10 EFI FourStroke Installation, Operation & Maintenance Manual

Spark Plug Inspection and Replacement

Damaged spark plug boots may emit sparks that can ignite fuel vapors under
the engine cowl, resulting in serious injury or death from a fire or explosion.
To avoid damaging the spark plug boots, do not use any sharp object or
metal tool to remove the spark plug boots.
1. Remove the spark plug boots. Twist the rubber boots slightly and pull off.
2. Remove the spark plugs to inspect. Replace the spark plug if electrode is
worn or the insulator is rough, cracked, broken, blistered, or fouled.
3. Set the spark plug gap to specification.
Spark Plug
Spark plug gap
4. Before installing the spark plugs, clean off any dirt on the spark plug
seats. Install plugs finger‑tight and then tighten 1/4 turn, or tighten to the
specified torque.
Description
Spark plug
MAINTENANCE
WARNING
!
26899
26946
Nm
20
86
26947
0.9 mm (0.035 in.)
lb‑in.
177
lb‑ft
–
eng