ROBBE JetForce Instruction And User's Manual page 8

Unlike rudder steerable boats, jet boats must have power applied to the motors in order for the boat to turn.
When making turns, decrease the throttle to reduce the probability of flipping the boat over. The boat will not
steer when coasting off power.
Never operate your boat in less than 3 inches (7.6 cm) of water.
CAUTION:
Running your boat in shallow water increases the chance of debris entering the jet pump. Verify that
the jet pumps are free of debris, as operating the boat with a blocked jet drive for a prolonged period
will damage the motor and ESC.
If you need to retrieve your boat from the water, use fishing equipment or another boat.
CAUTION:
Never operate your boat in extreme tempera-
tures or turbulent water.
O P T I O N A L T R I M A D J U S T M E N T S E R V O
You can install a servo that allows you to adjust the boat's trim via a 3-channel radio.
IMPORTANT:
This option is not available with the included radio system.
The servo tray fits a 1/18-scale or 1/16-scale servo. To install a trim servo in the servo tray:
1.
Use a 1.5mm hex driver to loosen:
•
the set screw holding the steering link push rods to the servo arm, and
•
the set screw holding the trim link push rod to the servo tray
2.
Disconnect the steering servo wire from the receiver.
3.
Use a 2mm hex driver to remove the 4 screws holding the servo tray to the jet pump.
4.
Insert a 1.5mm hex driver into the servo link end nut and use it as a handle to loosen the link end nut from
the radio tray.
5.
Install the servo in the radio tray.
Tip: Servo hold down screws are not included. We recommend M3 stainless steel button head screws with a
2mm hex head.
6.
Attach the servo link end nut to the trim servo control arm.
Tip: Over tightening the servo link end nut can cause your servo to burn out prematurely. Test the servo arm
movement by hand to ensure there is no drag or excessive friction.
7.
Use a 2mm hex driver to install the servo tray on the jet pump using the 4 M3 screws removed in Step 3.
8
8.
Power ON the ESC, allowing both the steering servo and the newly installed trim servo to center.
Instructions and User Manual
9.
10.
11.
Tip:
12.
13.
NOTICE:
CAUTION:
14.
Never attempt to retrieve a downed boat
by swimming to retrieve it.
Servicing the Drive Shaft
Always replace the drivetrain parts when they are damaged or show visible wear or injury and damage may result.
Lubricating the driveshaft is vital to the life of the drivetrain. The lubricant also acts as a water seal, keeping water
from entering the hull through the stuffing tube.
1.
2.
3.
4.
5.
6.
7.
8.
9.
Center out the steering nozzle and tighten the set screw using a 1.5mm hex driver.
With the trim servo powered and centered, install the servo arm perpendicular to the servo.
Slide the trim link push rod through the rubber bellow and into the servo link end nut.
Use marine grease on the link for smoother installation.
Set the steering nozzle trim to its desired position. Using a 1.5mm hex driver, tighten the set screw. This is
now the default trim setting until you make adjustments with the new trim servo.
Using your transmitter, actuate the servo up and down to find the maximum travel. Ensure the servo end
points are properly set.
If you do not properly set the servo end points damage to the servo and/or the jet pump will result.
Test the servo trim function in calm water and adjust the settings accordingly.
M A I N T E N A N C E
Remove the silicone cooling line from the brass fitting on the jet pump housing.
Use a 1.5mm hex driver to remove the bolts holding the steering and trim links from the steering and trim
assemblies on the pump. Use needle nose pliers to hold the nut that holds the bolt to the lever.
Use a 1.5mm hex driver to loosen:
•
the set screw holding the steering link to the steering servo arm
•
the set screw holding the trim adjustment link in place
Remove the trim adjustment link from the boat. Inspect the links for damage and set them aside, taking care not
to mix up the steering and trim adjustment links.
Use a 2mm hex driver to remove the 7 screws surrounding the main jet pump nozzle. These screws are held to
the hull by 2 plates that hold the nuts. If the plates and nuts loosen inside the hull, carefully remove them.
Gently pull the housing away from the hull by grabbing it at the base. It is normal for the rubber bellows to
come off the hull along with the nozzle.
Use a 2mm hex driver to remove the set screw that holds the drive shaft to the weighted motor coupler.
Remove the drive shaft from the boat. Use pliers to grab the shaft by the nut if removal by hand is difficult. Do
not use pliers on the drive shaft threads or damage will result.
Inspect the impeller and drive shaft for excessive wear or damage and replace them when necessary. A discolo-
red drive shaft indicates a lack of lubrication. Increase the amount of marine grease you are using. If you replace
the drive shaft, you must also replace the stuffing tube. See Replacing the Stuffing Tube for more information.