Hunter 49, Operator'S Manual

Page: 142 / 196

Hunter 50 • Engines and Transmissions
11.4
The raw water cooling system is described in detail in
your “Water Systems” (section 9) of this manual. The
internal engine cooling system is supplied by the engine
manufacturer. This system features a closed antifreeze
coolant bottled in a reservoir attached to the engine.
Coolant is circulated through the engine in separate
channels than the raw water cooling.
Note: Be sure the engine seacocks are open before you start
the engine. Failure to open them will cause damage to the
water pump impeller.
DANGER
! !
burns or other personal injury when pressure cap is
removed. Allow engine to cool. Open pressure cap
slowly to allow pressure to vent before removing
cap.
11.1.5 Emergency Equipment
Your engines are set up to operate under the toughest
conditions. However, should the oil pressure become
too low, or the engine overheat, alarms will sound at
the helm. There are several conditions that will sound
an alarm and save you from damaging your engines.
Be sure and study your documentation supplied by the
engine manufacturer to ensure you will know what the
alarm means should one sound on your boat.
11.2 Transmissions
The transmission has a reduction gear which drives
the propeller at a slower rotation speed than that of the
engine. g
Consult your OEM manual for complete transmission
information.
11.3 Operations and Maintenance
In the Underway Chapter, (Chapter 12) you will find
instructions on starting your engines. Also detailed in the
manufacturer’s documentation supplied with your boat,
you will find instructions on maintenance items that you
may perform yourself. Should you have any questions
regarding maintenance or operations not provided, be
sure and consult your boat dealer.
Important: Shift the transmission only when the engine speed
is at or below 1000 rpm. Shifting at higher engine speeds could
severely damage the boat, the transmission, and the engine.
Allow the transmission to remain in neutral for a few seconds
before reversing the rotation of the propeller.
11.3.1 Hydrolock
Hydrolock is caused by water entering the engine cylin-
ders through the exhaust. The following conditions can
cause hydrolock.
Engine shutdown: A sudden engine shutdown while the
boat is moving may force water into the exhaust system.
Anchored or adrift: Rough seas may cause rocking
severe enough to cause water to splash out of the muf-
flers into the engine while the engines are shut down,
anchored from the stern, pulling a sea anchor, or adrift.
Improper hoisting: Operators are sometimes tempted to
reduce hoisting time for propeller changes by hoisting only
the boat stern. Such hoisting can cause residual water in
the exhaust system to enter the engine cylinders.
WARNING
! !
Engine manufacturers do not warranty items dam-
aged by hydrolock.
11.3.2 Engine / Generator Exhaust
Your engine exhaust contains Carbon Monoxide! Be
sure and read the Boating Safety Chapter and know
the dangers and how to avoid them. Carbon Monoxide
will kill you, and in most situations, by the time you
know something is wrong it could be too late. Know
. Oil filler cap
. Dipstick
Fig. 11.3