increase in engine RPMs is evidence of cavitation. If
this occurs accidentally while running at full throttle,
immediately lower the drive trim and reduce the throttle
until the slipping stops. Have your dealer reset the trim
limit switch to avoid over trimming in the future.
If the prop slips at lower planing speeds, the drive may
be trimmed too high. Immediately lower the drive unit
until the prop “grabs” again to restore efficiency.
7. On performance boats, trimming out, in addition to rais-
ing the bow, also lifts the boat higher, gaining speed
because of less hull in the water.
8. The high–tilt trailering position of the stern drive is con-
trolled by a separate switch which is located on the
control handle, dash, or switch panel. Do not activate
this switch while underway. This can severely damage
the lower unit.
NOTE: Refer to your drive unit(s) instruction manual, or
your dealer, regarding the power trim controls installed on
your boat.
TILT/TRIM Control Switches - Outboards
On outboard engines equipped with power trim, read the
instructions provided by the engine manufacturer for cor-
rect usage.
On outboard engines without power trim, the trim angle
can be controlled by using the following “Rule of Thumb”: If
the bow runs low or heavy in the water, move the unit out
one or two pin hole settings. If the bow runs too high or
light in the water, move the unit in towards the transom
one or two pin hole settings.
Trim Tabs
If your boat is equipped with trim tabs you can use them to
adjust the boat’s trim to the optimum angle for load and
water conditions. Trim tabs add lift to the boat’s stern,
thereby changing the boat’s attitude (see Figure 3.4). This
lift can help the boat remain on plane at slower speeds
than if no tabs were used.
During one of your first boating expeditions, take the boat
out onto open water and experiment with the trim tabs.
After you get the boat on plane, set the tabs in various
positions and note how the boat reacts. This will give you a
3.15
WARNING:
Excessive trim will decrease maneuver-
ability, change steering characteristics, and may cause
“porpoising” (bow oscillates up and down) or “chine
walking” (rocking from side to side). USE POWER
TRIM WITH CARE.
STARBOARD TAB LOWERED
• STARBOARD STERN RISES
• PORT BOW LOWERS
PORT TAB LOWERED
• PORT STERN RISES
• STARBOARD BOW LOWERS
STERN
TRIM TAB
HULL
AS WATER PASSES UNDER
THE HULL AND HITS THE
TRIM TAB, THE STERN OF
BOAT IS PUSHED UP.
FIGURE 3.4 – TRIMMING WITH TRIM TABS
increase in engine RPMs is evidence of cavitation. If
this occurs accidentally while running at full throttle,
immediately lower the drive trim and reduce the throttle
until the slipping stops. Have your dealer reset the trim
limit switch to avoid over trimming in the future.
If the prop slips at lower planing speeds, the drive may
be trimmed too high. Immediately lower the drive unit
until the prop “grabs” again to restore efficiency
.
7.
On performance boats, trimming out, in addition to rais-
ing the bow, also lifts the boat higher
, gaining speed
because of less hull in the water.
8.
The high–tilt trailering position of the stern drive is con-
trolled by a separate switch which is located on the
control handle, dash, or switch panel. Do not activate
this switch while underway. This can severely damage
the lower unit.
NOTE:Refer to your drive unit(s) instruction manual, or
your dealer, regarding the power trim controls installed on
your boat.
TIL T/TRIM
Control Switches - Outboards
On outboard engines equipped with power trim, read the
instructions provided by the engine manufacturer for cor-
rect usage.
On outboard engines without power trim, the trim angle
can be controlled by using the following “Rule of Thumb”: If
the bow runs low or heavy in the water, move the unit out
one or two pin hole settings. If the bow runs too high or
light in the water, move the unit in towards the transom
one or two pin hole settings.
Trim T
abs
If your boat is equipped with trim tabs you can use them to
adjust the boat’s trim to the optimum angle for load and
water conditions. Trim tabs add lift to the boat’
s stern,
thereby changing the boat’s attitude (see Figure 3.4). This
lift can help the boat remain on plane at slower speeds
than if no tabs were used.
During one of your first boating expeditions, take the boat
out onto open water and experiment with the trim tabs.
After you get the boat on plane, set the tabs in various
positions and note how the boat reacts. This will give you a
3.15
WARNING:
Excessive trim will decrease maneuver-
ability, change steering characteristics, and may cause
“porpoising” (bow oscillates up and down) or “chine
walking” (rocking from side to side). USE POWER
TRIM WITH CARE.
ST ARBOARD T
AB LOWERED
• ST ARBO
ARD STERN RISES
• PORT BO
W LOWERS
PORT T
AB LOWERED
• PORT STERN RISES
• ST ARBO
ARD BOW LO
WERS
STERN
TRIM T AB
HULL
AS WA
TER PASSES UNDER
THE HULL AND HITS THE
TRIM T AB, THE STERN OF
BOA T IS PUSHED UP
.
FIGURE 3.4
–
TRIMMING WITH TRIM TABS