MJM Yachts 34z Express - Manual (Page 15)

CHAPTER 4 STEERING CONTROL SYSTEM
- 15 - 34z
Consult the user’s manual for specifics about your thruster. In general, thrusters are best used in
short bursts. Prolonged use may damage the motor, or at least trip the breaker. When not in a
situation where the thruster may be necessary, leave it turned OFF to avoid damage. Consider
the fact that your thruster gets DC power from the engine start battery, which is charged by the
engine’s alternator. If the engine is not running, or running at idle, the thruster can consume more
energy than the alternator can provide. It is possible to discharge the battery by over-use of the
thruster.
Turn on the bow-thruster by holding down the two left buttons (or turning the switch to ON with
some models) until the activation light appears. If the light does not appear, check to see that the
large red knob for the bow-thruster circuit breaker (below ignition panel) is pulled out.
When operating the bow-thruster, allow the propeller to come to complete
stop before reversing direction. Failure to do so may result in damage to the shear pin.
The bow-thruster zincs should be checked periodically and replaced if
significantly worn.
4.4 TRIM
TABS
While trim tabs are not necessary on the 34z, which runs at 3-5 degree angles, they do come in
handy to fine-tune the trim and running angle of the 34z. The trim tab breaker on the DC panel
must be ON for the unit to work. The trim tabs are wired intuitively, so by pushing down the
starboard tab, the bow leans down to starboard. (Actually, the port tab is going down to lift the
port aft corner of the boat).
Trim tabs aren’t necessary at low or high speeds. They are useful in lowering the bow for better
visibility or for slicing through a small chop at moderate speeds. At higher speeds when the boat
naturally runs flatter and when running downsea into the back of waves, it’s advisable to raise the
trim tabs for dry running and control, allowing the bow to lift.
Lenco trim tabs are powered by DC electricity on Hulls #5 and higher. On hulls #1 through #4
Bennett trim tabs operate by supplying DC electric power to a hydraulic pumpset, located aft by
the steering quadrant under the aft cockpit hatch. The level of hydraulic fluid should be
periodically checked in the clear reservoir.
4.5 AUTOPILOT OPERATION (Optional)
The Autopilot/Depth breaker (on the DC panel) must be ON for the autopilot to function. Check
the autopilot display and note the rudder angle indicator which helps in maneuvering the boat.
When the compass heading is displayed on the autopilot it is operational and can be activated by
pushing AUTO. The boat will then maintain the displayed heading. Push +1 or -1 for one degree
course corrections or +10 or –10 for ten degree increments.
The autopilot system is part of the hydraulic steering system. DO NOT
turn the wheel when the autopilot system is ON. Push STANDBY to switch back to manual
steering.
4.6 WINDSHIELD
WIPERS
The 34z is fitted with two windshield wipers. For specific instructions, refer to the user manual.
The wash feature is connected to your boat’s freshwater system and requires that the system be
pressurized (i.e. that the freshwater pump is ON). If the wipers are to be used in sub-freezing
temperatures, a separate system must be installed which utilizes anti-freeze.