WORLD CAT™
RIGGING INFORMATION
Note:
These are general recommendations
for the proper rigging of a World Cat. In ~
cases, however,
the experience of the installation
technician
regarding safe procedures
should prevail.
Motor Mounting
Transoms are pre-drilled during production
to allow for proper motor mounting. Transom
height is 25", requiring the use of x-long shaft 25") motors. The installation
height will be slightly higher than on a
conventional
monohull to allow cavitation
to occur within reasonable
limits to provide the best acceleration.
Generally, the cavitation plate height is the best reference to determine
which bolt hole to use - the plate should
be level with the bottom, or no higher than
'I."
above the bottom. Higher installations
may cause bow steering
conditions, may require the use of low water pickups to prevent overheating
and may also result in premature
blow-out of the props; therefore, extreme mounting heights are not recommended.
Motor mounting bolts should
be torqued to 40 ft. Ibs. (4.56 Kgm) ONLY. Re-torque mounting
bolts periodically,
but at least annually.
Motor Toe
It is recommended
that the relationship
between the two motors' direction of thrust (toe) be set at
zero to achieve the lightest steering effort and best performance.
To adjust toe, refer to the steering section
below.
Steering Adjustment
The dual cylinder hydraulic steering system features a "liquid tie-bar" to allow both
motors to respond to the helm in unison. (Refer to the diagrams
in this manual.) Occasionally,
it will be necessary
to realign the motors due to normal use. To align the motors, first center the starboard motor by turning the helm.
Then, open the system ball valve (located beneath the inspection
port on the dive platform) by turning it 90
degrees. This will isolate the port motor from the system and allow it to be moved manually. Center the port motor
by hand, then close the ball valve and replace the inspection cover port. Note: It may become necessary to purge
("bleed") the hydraulic system of air from time to time. Refer to the Teleflex
steering system bleeding instructions
on the next page.
Trim Tabs
Setting the trim tabs properly will provide uniform steering effort as the helm is turned to port and
starboard. The tabs serve to neutralize the torque effect of the motors on the steering system. For conventional
rotation motors, the tab will be set with trailing edge approximately
3/16" to the right. (The adjustment
is the same
for both motors, if both are standard rotation.) If a counter-rotation
motor is installed on the port side, that tab will
be set with the trailing edge approximately
3/16" to the left.
Tilt Angle
Install the tilt pin or limiting bolts slightly out to achieve a neutral (straight up & down) position of the
motors relative to the hulls. This will reduce any bow steering tendency
in the mid-speed range. For Yamaha
installations (no tilt pins), it is recommended
to trim the motors no further in than 1 bar on the tilt gauges.
Propeller Selection
There are a wide variety of OEM and after-market
propellers that will provide excellent
performance.
Your dealer can give customized
recommendations
based upon your specific requirements.
Generally, 3-blade stainless steel props offer better overall performance
than aluminum.
Propellers with full blade
area and cupping (Le. Mercury Mirage Plus) perform well on power catamarans.
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