ClimateRight CR-2550 Uživatelský manuál stáhnout pdf (Strana 128)

Vessel Operation

5-17

STERN DRIVE MANEUVERING

Stern drive boats do not have rudders. The boat uses a steering system

that directs the propeller thrust, by turning the stern drive unit where

the propeller is mounted. Normally maneuvering an I/O boat is easier

than a similar single screw vessel.

Directing propeller energy (thrust) makes slower speed maneuvering

easier. The propeller discharge current is turned from one side to the

other which results in turning forces. Rudder boats need water to ﬂ ow by

the rudder to be efﬁ cient. Stern drive units are designed to have reduced

shaft angle, so the propeller does not produce as much unequal blade

thrust and resistance as does a propeller on a single screw boat. Large

horsepower stern drive boats produce more thrust and steering torque

but Regal boats use power steering. Below is some basic information

on how single stern drive boats handle in normal conditions.

Gathering Headway

When a stern drive is not moving forward or reverse in the water and

the propeller is not turning, (shift in neutral) the boat will not react to

the helm steering wheel.

As soon as the vessel is shifted into forward gear the propellers action

creates a discharge motion and generates energy in the form of thrust.

If the stern drive is centered, the discharge motion is directed straight

back causing the vessel to advance forward.

You may notice that if you advance the throttle quickly in initial take-off

(make sure you have a ﬁ rm grip on the wheel), the boat has a tendency to

pull the stern of the vessel to starboard. There is a trim tab (also serves

as a sacriﬁ cial anode) located on the vertical drive housing just to the

top of the propeller blade. This trim tab helps compensate for the low

speed steering torque. Once the boat increases headway the propeller

is operating in a faster water ﬂ ow this torque effect decreases.

Sometimes the trim tab may need adjustment on stern drive models.

Contact your Regal dealer for further information or consult your

engine manufacturer’s manual.