Hamilton Jet HJ241, Manual

Page: 50 / 202

3.16
3 DESIGN BASICS
3.7 E
NGINE
L
OCATION
& M
OUNTING
HJ-241 / HSRX
The Jet unit water offtake can be used for a deck
cleaning hose but the pressure is not high enough
for a fire hose.
CONVENTIONAL WATER PICK-UP:
Alternatively a cooling system separate from the Jet
Unit can be fitted to the engine maker’s
specifications. The water pick up points must NOT
be directly ahead of the Jet Unit intakes and should
be well to the side of the area forward and the same
width as the intake opening.
3.7.4 Engine Systems
Engine wiring, instrumentation and throttle systems
are all conventional. Follow the manufacturers
recommendations.
WITH STEEL HULLS.— Ensure the controls do not
electrically connect the Jet Unit to the hull.
3.7.5 Exhaust Systems
The engine exhaust system can be any conventional
system approved by the engine manufacturer.
Engine exhausts should be sited above the waterline
and away from the Jet Units.
If engine exhausts are located near the Jet Units,
water containing exhaust gases can be ingested by
the Jet Unit when the vessel is moving astern. This
can cause loss of thrust and control of the Jet Unit.
3.7.6 Governor Settings
Refer to Section 5.6.5 Governor Settings .
C
AUTION
If a gearbox or clutch is fitted to
the engine, a conventional hull
water pick-up and engine raw
water pump must be used.
C
AUTION
Ensure that the engine cooling
water pick up is not directly
ahead of the Jet Unit Intake, but
well to the side to avoid turbulent
water flow into the Jet.
Figure 24: Exhaust System Layout
WATER LINE
WATER
ONLY
EXHAUST GASES
ASTERN
BOAT GOING
KEEL
CHINE
EXHAUST OUTLETS
FLOW
WATER
EXHAUST
GASES
BOAT GOING
ASTERN
KEEL
CHINE
EXHAUST OUTLETS