Volvo Penta TAMD74A, Operator'S Manual

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22
Operation
Forward–Reverse
1. Slow the engine speed to idling and allow the boat to
loose most of its speed.
2. Move the lever to neutral. Wait for approximately two
seconds.
3. Move the lever to reverse. Wait for approximately two
seconds and then increase the engine speed gradually.
IMPORTANT! A direct forward–reverse manoeuvre
can damage the transmission and engine. It is there-
fore always necessary to stop with the lever in neutral
for a few seconds. Allow the boat to loose most of its
speed as well before engaging. If the speed of the
boat is too high, there is a risk of the propeller torque
being so high that the engine will stop and start re-
versing, causing the engine to break down.
Forced propeller rotation
(E.g. when towing)
When towing, sailing, anchoring in strong currents, etc.,
the propeller can make the propeller shaft rotate even
though the engine is stationary. This rotation may be un-
comfortable and can damage the reverse gear.
IMPORTANT! The propeller shaft can be allowed to
rotate with a stationary engine for up to 6–8 hours.
After that period, the engine must be started and run
for at least 5 minutes to enable lubrication and cooling
of the reverse gear.
In cases where the propeller shaft may rotate faster than
during normal operation, e.g. when sailing, a temperature
gauge should be fitted to monitor the oil temperature. Max.
permitted temperature is 110°C (230°F) for Twin Disc and
95°C (203°F) for ZF (MPM) reverse gear.
A shaft brake must be fitted if the above directions cannot
be followed or if it is necessary to stop the shaft for rea-
sons of comfort. On isolated occasions, the propeller shaft
flange can be locked mechanically in a suitable manner.