Spark Plug Inspection And Replacement; Fuse Replacement - Mercury 40 Operator's 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 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

Fuse Replacement

IMPORTANT: Always carry spare 20 AMP fuses.
The electrical wiring circuits on the outboard are protected from overload by fuses in the wiring. If a fuse is blown,
try to locate and correct the cause of the overload. If the cause is not found, the fuse may blow again.
Open the fuse holder and look at the silver colored band inside the fuse. If band is broken, replace the fuse. Replace
fuse with a new fuse with the same rating.
MAINTENANCE
WARNING
!
ob00375
ob00423
1.0 mm (0.040 in.)
Nm
27
55
ob00424
lb. in. lb. ft.
20