MAINTENANCE
SERVICE MANUAL NUMBER 25
90-861328--1 NOVEMBER 1999
Page 1B-3
Maintenance Schedules
Maintenance Intervals
Maintenance intervals and the tasks to be performed, as shown in this current schedule, or
as found in a previously printed schedules, are generally based on an average boating
application and environment. However, individual operating habits and personal mainte-
nance preferences can have an impact on the suggested intervals. In consideration of these
factors, Mercury MerCruiser has adjusted some maintenance intervals and corresponding
tasks to be performed. In some cases, this may allow for more individual tasks to be
performed in a single visit to the serving dealer, rather than multiple visits. Therefore, it is
very important that the boat owner and servicing dealer discuss the current Maintenance
Schedule and develop appropriate maintenance intervals to coincide with the individual
operating habits, environment, and maintenance requirements.
CAUTION
Always disconnect battery cables from battery BEFORE working around electrical
systems components to prevent injury to yourself and damage to electrical system
should a wire be accidentally shorted.
Gas Sterndrive
Routine Maintenance *
Each
Day
Start
Each
Day
End
Weekly
Every
Two
Months
Check crankcase oil (interval can be extended based on experi-
ence).
If operating in salt, brackish or polluted waters, flush cooling sys-
tem after each use.
Check drive unit oil level, trim pump oil level and power steering
pump fluid level.
Check water pickups for debris or marine growth. Check water
strainer and clean. Check coolant level.
Inspect drive unit anodes and replace if 50 percent eroded.
Inspect fuel pump sight tube and have pump replaced if fuel is
present.
Check battery connections and fluid level.
Lubricate propeller shaft and the retorque nut (if operating in only
freshwater, this maintenance may be extended to every four
months).
Operating in Saltwater Only: treat engine surface with corrosion
guard.
Clean air filter every 50 hours of operation.
* Only perform maintenance which applies to your particular power package
Standard Models
Horizon Models
