Hamilton Jet HJ212, Installation And Service Manual

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Appendix
Installation and Service Manual
To stop sideways movement

Set the steering to dead ahead, throttle RPM to idle and reverse to zero speed before the vessel reaches
the required position.

Alternatively set the controls to start sideways movement in the opposite direction until the vessel stops
sideways movement then set the steering to dead ahead, throttle RPM to idle and reverse to zero speed.
Emergency manouvering
Single jet unit
The vessel can be partially manoeuvred by raising the reverse duct with a rope and lowering it under its own
weight. The engine must be kept at idle RPM. Refer to section: Manual control of steering nozzle and reverse
duct on page 10-41.
Multiple jet units
Shut down the engine driving the jet without reverse and manoeuvre using the other jet(s).
Cruising
Running at speed with a partially blocked inlet grill or debris on the impeller will result in
cavitation damage to the jet unit.
Care must be taken to prevent cavitation damage to the jet units, as described below:

Acceleration should be gradual. Full power cannot be used at low vessel speeds such as when operating
on one engine only.

If there is a blockage of the jet unit, the engine will run at a higher than normal RPM, the vessel will
accelerate slowly and best speed will be reduced. If such symptoms are noticed, immediately slow the
vessel and clear the blockage.

In conditions of severe weather or overload, the engine speed should be reduced accordingly.
Shallow Water Operation
Do not run the jet unit if the vessel has run aground as damage may occur to the impellers
and stator.
It is important to avoid pumping stones, sand, etc, through the jet unit as this will blunt and wear the
impeller.
The following diagrams illustrate good and bad practice:
Figure 19: High Speed Planing in Shallow Water
At high planing speeds, shallow water operation is not a problem until the vessel is nearly grounded.
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