Lubrication Points; Gearcase Lubrication - Mercury 25 Series Owner's Manual

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

Lubrication Points

It is important to inspect and maintain your outboard motor
regularly. Maintenance intervals should be determined according
to the number of hours or number of months, whichever comes
first. For periodic servicing and maintenance guidelines, please
contact your local Mercury dealer.
Item
Sliding and
rotating parts
Grease fittings

Gearcase Lubrication

When adding or changing gearcase lubricant, visually check for
the presence of water in the lubricant. If water is present, it may
have settled to the bottom and will drain out prior to the lubricant,
or it may be mixed with the lubricant, giving it a milky colored
appearance. If water is noticed, have the gearcase checked by
your dealer. Water in the lubricant may result in premature bearing
failure or, in freezing temperatures, will turn to ice and damage the
gearcase.
Remove the fill/drain plug and examine the magnetic end for metal
particles. A small amount of metal filings or fine metal particles
indicates normal gear wear. An excessive amount of metal filings
or larger particles (chips) may indicate abnormal gear wear and
should be checked by an authorized dealer.
MAINTENANCE
Every 50 hours or 3
months
Yes
Yes
1.0 mm (0.035 in.)
Nm
27
Every 100 hours or 6
months
Yes
Yes
90
lb. in. lb. ft.
20
Action
Apply and pump in
grease
Apply and pump in
grease