Changing a Propeller and Horizontal Thruster Nozzle

The Pro 4 propellers are held on smooth shafts using a collet similar to the ones used to hold drill bits. Also note that the Pro 4 uses counter rotating propellers and a smaller diameter propeller for the vertical thruster. VideoRay recommends that you only remove one propeller at a time to avoid using the wrong propeller for that location.

If the propellers do get mixed up, the following will help determine the correct locations.

• The vertical propeller is smaller - 60 mm (2.4 inches) versus 100 mm (4 inches) for the horizontal propellers.

• When viewing the horizontal propellers from the rear, with one blade pointing up, the blade pointing up should curve toward the center. The two blades pointing up should form the shape of an "O."

To remove a propeller, loosen the nut a few turns (do not remove it), and pull the propeller from the shaft.

When pulling on the propeller, pull close to the hub. Do not pull on the blades. Doing so can break a blade.

If the propeller does not come off easily, tap the dome of the nut a few times while pulling on the propeller. This should loosen the collet and allow the propeller to be removed easily.

To install a propeller, slide it over the shaft until it stops. The propellers are designed to fit just right. If the propeller is tight against the cartridge seal, or there is a significant gap, make sure the cartridge seal is seated or that the propeller does not have something in it.

Once the propeller is installed all the way onto the shaft, tighten the nut. It should be tight enough so that while holding the propeller, the edge of the blades will start to hurt a little while turning the nut.

Horizontal Thruster Nozzle

To remove a horizontal thruster guard, first remove the propeller. Grasp the thruster nozzle and rotate it counter clockwise (when viewed from the rear). This should loosen the thruster cone nut. Unscrew the thruster cone nut and slide the thruster nozzle off the thruster tube.

To install a horizontal thruster, slide it over the thruster tube. Install the thruster cone nut and screw it on until it is snug. Grasp the thruster nozzle and turn it clockwise while turning the thruster cone nut until the assembly is tight.