The skeg, the fin-like appendage of the very bottom of an outboard motor, is the component that is usually first to sustain damage if the boat runs aground. The unique design of the Blackfin skeg helps to channel water around the engine and reduce vibration noise; its high-impact composite construction gives it flexibility to ward off damage in the event of an impact. Installing a Blackfin skeg, which fits over the existing skeg on your outboard, should take an hour or less.
Sand down the skeg already on your outboard and use the file to smooth out any bent areas. Clean the skeg with soap and rinse with water. Let it dry.
Fit the Blackfin skeg onto the motor and use the pencil to mark on both sides where it meets the motor. Be sure to rotate the prop to check for proper clearance. Mark the location of the drain screw. Using the utility knife, trim out the area to permit access to the drain screw.
Place tape over the drain screw. Put tape over the top of the Blackfin skeg below its top edge. Taping these areas protects them against the adhesive you will use to attach the skeg.
Load the cylinder of adhesive that is supplied with your Blackfin skeg into a caulk gun; lay a bead of the adhesive on both sides of the gear housing, where it meets the skeg. Apply the adhesive to the insides of the skeg. Use a zigzag pattern; this create air pockets that help the adhesive set correctly.
Slide the Blackfin skeg into position. Rotate the prop to check again for clearance.
Remove the tape and wipe off any excess adhesive that's on the gear housing with a clean cloth.
Use your finger to make a continuous, smooth seal all the way around the skeg, making a watertight seal. Apply more adhesive if necessary.
Secure the Blackfin skeg to the gear housing with duct tape while the adhesive sets.
Check the prop rotation for clearance once again. Allow the adhesive to cure for 72 hours, then remove the tape.
