How The Jet Drive Operates; Stopping The Boat In An Emergency - Mercury jet 20 Manual

How the Jet Drive Operates

A jet driven boat has substantially different handling characteristics compared to a propeller driven boat. It is
recommended that the operator adjusts to these characteristics by experimenting in open water at both high and
low speeds.
The driveshaft driven impeller draws water up through the water intake and then redirects it at a high pressure
through the water outlet nozzle to create forward thrust. To obtain reverse, the reverse gate moves over the
outlet nozzle to direct the water in the opposite direction.
a - Water intake
b - Water outlet nozzle
When the jet drive is in neutral, the impeller continues to rotate. However, the reverse gate is positioned so that
some of the forward thrust is diverted to create reverse thrust. This approximate balancing of forward and reverse
thrust will minimize any boat movement. Because the impeller is always rotating and creating thrust when the
engine is running, the boat may tend to move slowly forward or backward. This is normal for a direct‑drive jet
driven boat. The operator should be aware of this and use caution whenever the engine is running.
Avoid injury resulting from contacting the rotating impeller or having hair, clothing or loose objects drawn into
the water intake and wrapping around the impeller shaft. Stay away from the water intake and never insert
an object into the water intake or water outlet nozzle when the engine is running.
The jet drive is always drawing water into the housing when the engine is running. Do not operate the jet drive
with the grate removed from the water intake. Keep hands, feet, hair, loose clothing, life jackets, etc., away from
the water intake. Never insert an object into the water intake or water outlet nozzle when the engine is running.

Stopping the Boat in an Emergency

A jet powered boat has emergency stopping capability unique to this form of propulsion.
Using the emergency stopping capability of the jet drive will slow down the boat in an emergency. However,
sudden stopping may cause the occupants in the boat to be thrown forward or even out of the boat. This
action may result in serious injury or death.
OPERATION
a
c -
WARNING
!
WARNING
!
25
b
c
Reverse gate
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