Volvo Penta D9-425, Operator'S Manual

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Operation
Operation
Shifting between forward and reverse should be done at id-
ling. Shifting at higher engine speeds can be uncomfortable
for passengers and cause unnecessary stress on the stern
drive/reverse gear, or cause the engine to stop.
If you attempt to shift gear at an excessive engine speed, a
safety function cuts in automatically, and delays shifting
until engine speed has fallen to 1000 rpm.
Always do a forwards/reverse operation as follows:
1. Reduce engine speed to idle and let the boat more or
less lose way.
WARNING! Never shift to reverse when the boat is
planing.
2. Move the control lever to neutral with a rapid, distinct
movement. Make a brief pause.
3. Then move the control lever to reverse with a rapid, dis-
tinct movement and increase engine speed.
IMPORTANT ! If the boat has twin engines, it is im-
portant that both should be running during reversing
maneuvers, to avoid the risk of water entry (via the
exhaust pipe) into the stationary engine.
1
2
3
Propeller shaft brake
In certain conditions, the propeller can make the propeller
shaft rotate when the engine is stopped. This parasitic rota-
tion is uncomfortable, and can damage the reverse gear
since its oil pump, which is driven by the input shaft, is sta-
tionary together with the engine.
The propeller shaft can be permitted to rotate with a statio-
nary engine for up to 6-8 h. After this, the engine must be
started and run for at least 5 min to lubricate and cool the
reverse gear.
If the shaft is likely to rotate faster than in normal operation,
such as when sailing, a temperature gauge should be instal-
led to monitor the oil temperature.
Maximum permissible temperature is 95°C for the ZF re-
verse gear.
When the above-mentioned rules can not be met, or if you
want to stop the shaft for comfort reasons, a shaft brake
has to be installed. On isolated occasions, the propeller
shaft flange can be locked mechanically by some suitable
means.