GENERAL INFORMATION
ZT350 Installation Manual
2-5
Steering Tie Bar Considerations
12/05
© 2007 Yanmar Marine International
STEERING TIE BAR
CONSIDERATIONS
NOTICE: The use of multiple stern-drives requires
a careful consideration of the type of steering
system that should be used.
CAUTION!
Failure to observe the recommended
tie bar arrangements could result in serious
damage to the steering and / or power trim
system components. This damage could
adversely affect boat control.
Internal Tie Bar Only
This system is recommended for vessels that
operate at speeds up to 50 knots (58 mph).
It is a direct connection between the slave
stern-drive and the stern-drive that is directly
connected to the factory power steering output.
This internal tie bar is available in a variety of
lengths from Yanmar. Contact your Yanmar dealer
or distributor.
Internal and External Tie Bar
This system is recommended for vessels that
operate at speeds from 50 to 60 knots (60 to 70
mph) or for the benefit of reduced steering
backlash.
Usually, external tie bars are attached at the aft
power trim cylinder bosses, but if one drive is
trimmed differently than the other, undue stress on
the system is introduced. For this reason, dual trim
control equipment should be installed to limit the tilt
differential between the two drives to 20°.
NOTICE: When using an internal power steering
system, Yanmar does not recommend the use of an
external tie bar by itself. This can cause excessive
loads on the steering components and may result in
an increase of the play in boat steering.
External Power Steering with an
External Tie Bar
This system is recommended for vessels that
operate at speeds of 70 knots (80 mph) or greater
or for the ultimate in reduced steering backlash.
This system does not use an internal tie bar, but
requires dual trim control equipment.
and External Tie Bar on page 2-5
.
CORROSION CONTROL
It is the boat designer's responsibility and/or the
re-powering engineer's responsibility to design the
proper systems and equipment to control and
reduce the possibility of galvanic corrosion.
To help control the effects of galvanic corrosion,
Yanmar Marine ZT350 stern-drives come with
several anodes and an electronic anticorrosion
system (Y-CaPS) that protect the stern-drive in
moderate corrosive conditions. However, it is
essential that the owner/operator frequently
monitor the anodes for wear, inspect the stern drive
for corrosion and replace the anodes often enough
to provide a sacrificial surface for the electrical
current to attack. Galvanic isolators are also
available from the aftermarket (not supplied by
Yanmar) to block stray current while still providing a
path to ground for dangerous shock currents.
Shore Power
Vessels that are connected to shore power require
additional protection to prevent destructive low
voltage galvanic currents from passing through the
shore power ground wire. A galvanic isolator is
available to block these currents while still providing
a path to ground for dangerous shock currents.
NOTICE: If AC shore power is not isolated from the
boat ground, the Y-CaPS and anodes may be
unable to neutralize the increased galvanic
potential.
