Mercury 300XS OptiMax User Manual

MAINTENANCE
66
EVERY 200 HOURS OR ONCE EVERY TWO YEARS,
WHICHEVER OCCURS FIRST
• Replace water separating fuel filter.
• Check the spark plug gap and replace if necessary.
BEFORE PERIODS OF STORAGE
• Refer to Storage section.
Flushing the Cooling System (Powerhead)
Flush the internal water passages of the engine with fresh water
after each use in salt, polluted or muddy water. This will help
prevent a buildup of deposits from clogging the internal water
passages.
a
b
or36-1
a - Plug located on fitting
b - Water hose
1. Remove the plug from fitting in the bottom cowl.
2. Attach a water hose to the fitting. Turn on the water and flush
for three to five minutes.
NOTE: The engine can be stopped or operated at idle speed when
flushing the cooling system. Do not flush engine using a water
system that exceeds 310 kPa (45 psi).

Mercury 300XS OptiMax Specifications

General

Engine Type	2-Stroke
Horsepower	300 HP
Alternator Output	60 amp / 756 watt
Gear Ratio	1.75:1
Starting System	Electric
Fuel System	2-Stage Direct Fuel Injection (DFI)
Weight	505 lbs / 229 kg
Cylinders	6
Steering	Hydraulic
Shaft Length	25"