Spark Plug Inspection And Replacement - Mercury 135 Optimax Operation And Maintenance Manual

Spark Plug Inspection And Replacement

Avoid serious injury or death from fire or explosion caused by damaged spark plug boots. Damaged spark plug
boots can emit sparks. Sparks can ignite fuel vapors under the engine cowl. To avoid damaging spark plug
boots, do not use any sharp object or metal tool such as pliers, screwdriver, etc. to remove spark plug boots.
1. Remove the spark plug leads. 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.
MAINTENANCE
WARNING
!
0.80 mm (0.031 in.)
45
ob00422
ob00375
ob00423
ob00424