Trailering Your Boat; Propeller Selection - Volvo Penta 4.3OSi-B Operator's Manual

Trailering your boat

Before moving your boat, check the ground clearance of
the drive unit. When trailering, the drive unit may be in the
up or down position. There must be at least approx. 15
inches (40 cm) clearance between the lower gear unit and
the ground. If the clearance is less than 15 inches (40 cm),
raise the drive unit.
Caution!
Be very careful when you back out of driveways or
cross railroad tracks, so that the lower gear unit does
not hit the ground.
Make sure that the boat fits the trailer properly. In many
cases, loss of performance and speed is due to improper
trailer support and too much tie-down pressure, which
causes the boat bottom to deform. The boat should rest
firmly on the trailer with maximum tie-down pressure ap-
plied at the bow and transom only.

Propeller selection

Your Volvo Penta dealer has chosen a propeller designed
to deliver top performance and economy under most condi-
tions. To obtain the maximum percentage of available horse-
power, the engine RPM at full throttle should be in the speci-
fied full throttle operating range. Refer to Specifications
section for full throttle RPM range.
Propellers that allow full throttle operation at the upper end
of the RPM range provide faster planing time for water ski-
ing or similar activities. Propellers that place full throttle
operation RPM in the middle of the range provide improved
cruising fuel economy.
• If the engine's full throttle RPM with a normal load is
below the specified range or on the low side of the
range (1), use propellers with less pitch to increase
the RPM.
• If the engine's full throttle RPM exceeds the speci-
fied range (2), use propellers with higher pitch to
decrease the RPM.
Engine damage can result from incorrect propeller selec-
tion that
1. Prevents engine RPM from reaching the specified full
throttle operating range (e.g., laboring engine.) Install
lower pitch propeller(s).
2. Allows engine RPM above the specified full throttle
operating range (e.g., overspeeding engine). Install
higher pitch propeller(s).
Caution!
D-series aluminum propeller sets are not recom-
mended for use on Duoprop-equipped boat and engine
combinations that are capable of speeds in excess of
43 MPH (35 knots). F-series stainless steel propeller
sets should be used in these applications.
If you use D-series aluminum propeller sets, you must
also use an in-trim limiter kit. See your Volvo Penta
dealer.
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