Mercury 40 Jet Manual page 83

1. Remove the spark plug boots. Twist the rubber boots slightly
and pull off.
2. Remove the spark plugs to inspect. Replace 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 spark plugs, clean off any dirt on the spark
plug seats. Install plugs finger‑tight, and then tighten 1/4 turn
or torque to specifications.
Description
Spark plug
MAINTENANCE
1.0 mm (0.040 in.)
75
26899
26946
26947
Nm lb. in.
27
lb. ft.
20