Mercury INSTALLATION MANUAL D7.3L D-TRONIC - Manual (Page 17)

D7.3L D-TRONIC DIESEL ENGINES - BRAVO MODELS
Page 17 of 90
Propeller Selection
GENERAL INFORMATION
IMPORTANT: Installed propeller must allow engine to run at its specified maximum
wide-open-throttle revolutions per minute (rpm). Use an accurate service tachometer
to verify engine operating rpm.
It is the responsibility of the boat manufacturer and/or the selling dealer to equip the power
package with the correct propeller(s). Specified engine wide-open-throttle (WOT) and oper-
ating rpm range are listed in the “Operation and Maintenance Manual” attached to the en-
gine.
Select a propeller that will allow the engine power package to operate at or near the top end
of the recommended wide-open-throttle operating rpm range with a normal load. High rpm,
caused by an excessive trim angle, should not be used in determining correct propeller
selection.
If full throttle operation is below the recommended range, the propeller must be changed
to prevent loss of performance and possible engine damage. On the other hand, operating
an engine above the recommended operating rpm range will cause higher than normal wear
and/or damage. Generally, there is a 200 rpm change between propeller pitches.
After initial propeller selection, the following common problems may require that the propel-
ler be changed to a lower pitch:
• Warmer weather and greater humidity cause an rpm loss.
• Operating in a higher elevation causes an rpm loss.
• Operating with increased load (additional passengers, pulling skiers, etc.).
For better acceleration, such as is needed for water skiing, use the next lower pitch propel-
ler. However, do not operate at full throttle when using the lower pitch propeller but not pull-
ing skiers.
Because of the many variables of boat design, only testing will determine the best propeller
for a particular application. Available propellers are listed in the “Quicksilver Accessories
Guide.”
See “BOAT-IN-THE-WATER TESTS, Maximum rpm Test” in the power package Installation
Manual.
RPM REV-LIMITER
IMPORTANT: When selecting a propeller consider this additional information:
The engines listed in the following chart are equipped with a device that limits engine
rpm. Be sure that propeller being used does not allow engine to run against limiter,
as a significant loss in performance will result.
Engine rpm
MCM Model
Engine Recommended
Operating rpm Range
Rpm Limiter Setting
(Begins At:)
D7.3L D-Tronic 3600-3800 3850
D7.3L D-Tronic LD 3400-3600 3650