C. Prop Slip
When traveling through water a propeller is unable
to get a complete bite because of the ﬂuidity of water.
“Prop slip” is usually expressed as a per cent of the
computed theoretical speed. Twenty -ﬁve to thirty-ﬁve
percent prop slip is common for a cruiser-type boat
operating at cruising speed.
Changing either diameter or pitch will have an effect
on engine speed and prop slip, and in turn, directly
effect the performance of a boat. The propellers
included with each Four Winns boat provide the best
general performance based on data obtained from
on-the-water testing of that model. Variations in load,
operating conditions, environment, the individual
engine and hull performance may necessitate the
purchase and use of another propeller(s).
Figure E6: Prop Installation
Should it be necessary to change propellers,
always use an appropriate propeller removal
tool or “Prop Puller.” DO NOT attempt removal
using a hammer. Damage to the propeller or
propeller shaft can result.
Under your normal load conditions, the engines
should turn within the maximum RPM range when at
full throttle. If the engines exceed the recom mended
RPM, an increase in pitch or diameter is required.
If the engine RPM is too low, a decrease in pitch or
diameter is required.
Always check shaft rotation before propeller installa-
tion. A right hand rotation propeller must be installed
on the prop shaft connected to a starboard engine.
Similarly, a left hand prop must be connected to the
port engine shaft. The propellers must rotate outboard
The load carried in a boat will directly affect perfor-
mance of the engine. If an engine that is not develop-
ing full power, be sure the engine is properly tuned
and load conditions are those normally experienced,
before changing propellers.
Be sure the propellers are of the correct blade
conﬁguration, diame ter, pitch, and shaft size to assure
good performance. For additional information on
factors affecting performance and/or assistance with
your selection, please consult your Four Winns dealer.
For twin engine installations, always check
drive shaft rotation before propeller installation.
A right hand rotation propeller must be
installed on the starboard propeller shaft.
Similarly, a left hand prop must be installed
on the port propeller shaft.
E - 6 ENGINE COOLING SYSTEMS
A. Raw Water Cooling - Stern Drives & Inboards
For shipping reasons, the propellers are not factory
installed. Initial installation of the propellers will be
performed by the dealer during pre-delivery service.
See Figure E6.
Certain stern drive and inboard engines utilize a raw
water cooling system. This cooling system is a
seawater system. Seawater (raw) water is taken in
through water inlets on the both sides of the lower
gear unit of the stern drives models or by thru-hull
intake scoops with strainers (inboards). Water
pumped to the engine by the seawater pump is
circulated through the engine by the engine circulating
pump. A thermostat controls the engine operating
temperature by determining the amount of water to be
taken in, recirculated and discharged. On stern drive
models, the water is discharged through an idle
Engines, Drives and Instrumentation - Section E
Owner’s Manual Page 58
|Categories||Four Winns Manuals, Four Winns V-Series Manuals|
|Tags||Four Winns V375|
|Document Type||Owner's Manual|
|Product Brand||Boats and Cruisers, Four Winns. For support contact your dealer at http://www.fourwinns.com/locate-dealer.aspx|
|Document File Type|
|Wikipedia's Page||Outboard Marine Corporation|
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