Mercury 300XS OptiMax - Spark Plug Inspection and Replacement

MAINTENANCE
67
Flushing the Cooling System (Lower Unit)
!
WARNING
To avoid possible injury when flushing, remove the propeller.
Refer to Propeller Replacement.
a
b
c
d
d
or37-1
a - Fleet Master and
Torque Master
gearcase
b - Sport Master gearcase
c - Water hose
d - Flushing attachments
1. Remove the propeller. Refer to Propeller Replacement.
2. Fleet Master and Torque Master gearcases – Install the
appropriate flushing attachment so the rubber cups fit tightly
over the strut intake holes. Attach the Dual Water Flush Seal
over the nose inlets.
3. Sport Master gearcases – Install the appropriate flushing
attachment so the nose cone cup fits tightly over the intake
holes.
4. Attach a water hose to the flushing attachment. Turn on the
water and adjust the flow so water is leaking around the rubber
cups or nose cone cup to ensure the engine receives an
adequate supply of cooling water.
5. Start the engine and run it at idle speed in neutral shift position.
6. Adjust water flow so excess water continues leaking out from
around the rubber cups or nose cone cup to ensure the engine
is receiving an adequate supply of cooling water.