Volvo Penta D9-425, Operator'S Manual

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Operation
Cruising speed
Avoid operation at full throttle, for best fuel economy. We re-
commend a cruising speed which is at least 10% below the
maximum engine speed at full speed (full throttle). The maxi-
mum engine speed will vary due to propeller choice, load and
sea conditions, but it should be in the full throttle range.
Full throttle range:
D9 rating 3 .......................... 1900–2280 rpm.
rating 4 .......................... 2400–2650 rpm.
rating 5 .......................... 2300–2600 rpm.
If the engine does not reach the full throttle range, this could
be caused by a number of factors which are noted in the
“Fault tracing” chapter. If the engine speed exceeds the full
throttle range, select a coarser pitch propeller. Ask your
Volvo Penta dealer for advice.
Synchronizing engine speed
When driving with twin engines, both the operating economy
and comfort can be increased when the engines are opera-
ting at the same engine speed (rpm).
The synchronization function is indicated by a blue equals
sign (1) on the EVC control panel.
When the synchronization function is activated, the engine
speed (rpm) of the starboard engine is automatically adjus-
ted to that of the port engine. The synchronization function
is activated automatically if the following conditions are met.
1. The engine speed levers for both engines are in (approx-
imately) the same position.
2. The engine speed on both engines must exceed 800 rpm.
NOTE! The synchronizer is disengaged as soon as the
conditions are no longer met.
1