Installing an Outboard Rigging Tube

Outboard rigging tubes help protect cables, wires and hoses from damage.

Installing an outboard motor rigging tube
Once you have completed the installation, hook the engine up to cooling water and start it up to ensure that each of the cables, wires and hoses is connected and functioning properly. Tim Barker

The bundle of cables, wires and hoses that extend from the boat to the outboard motor(s) delivers essential fuel, electrical power, and throttle and shift commands, as well as providing feedback to the helm on engine performance and health.

Outboard rigging tubes protect these critical connections from wear, damage and UV deterioration. The ribbed plastic conduit is flexible enough to move as an outboard turns or tilts, yet is sturdy and kink-resistant. It also makes for a tidier motor installation. 

The first step is to procure the parts, which include a rigging flange (such as the Sierra Part No. 18-9761 or T-H Marine Part No. RF-1CP-DP) for the point where the rigging bundle emerges from the boat, an adapter for the engine rigging port, and the tube. This will be 2- or 2 ½-inch OD, depending on the engine brand. Make sure the flanges and adapters match the diameter of the rigging tube.

The tube should be long enough to easily reach between the rigging port and boat as the engine sweeps from side to side and tilts up and down. Use the length of the existing bundle between the engine and boat as a baseline, then add 2 inches. Trial-fit the tubing before you cut the hose to length.

Skill Level: 1.5 of 5

Finish Time: Approx. 4-5 hours

Tools and Supplies

  • Rigging hose ($79.99 per 10 feet of 2-inch OD,
  • Rigging flange ($8.29, Sierra Part No. 18-9761 molded plastic,
  • Rigging flange with fuel hose port to accommodate fuel primer bulb ($15.95, T-H Marine Part No. RFFHP-1-DP molded plastic,
  • Rigging flange hose union to accommodate fuel primer bulb ($10.30, T-H Marine Part No. RFHU-1-DP molded plastic,
  • Outboard rigging port adapter (check with engine manufacturer)
  • No. 10 stainless-steel screws (3)
  • Phillips screwdriver
  • Socket wrench set
  • Tape measure
  • Power drill and 1/8-inch bit
  • Marking pencil
  • Marine silicone sealant
Disconnecting outboard motor rigging
Disconnect the Motor Rigging Tim Barker

Tilt down the outboard and remove the engine cowling. (You might need to remove the lower engine pan too.) Disconnect the battery cables from the battery posts. Now disconnect any cables, wires, hoses and tubes that run through the rigging port to the engine. Pull all the rigging away from the engine. Plug the disconnected fuel hose with a clamped bolt to prevent spills. Remove the old rigging boot from the boat, and slide it down and off the rigging bundle. Patch or seal any screw holes left from the old rigging boot.

Moving wiring through tube
Snake the Rigging Through the Tube Tim Barker

Cut off any zip ties and remove any protective sheathing on the rigging bundle, then snake it through the new rigging tube components: first, through the rigging flange, then the rigging tube, and finally through the engine rigging port adapter. You might find it necessary to use an electrician’s snake or pull cords to thread the items through the tube. If necessary, first snake the larger-diameter items, such as the main electrical harness, which often has a large plug on the end, then the smaller ones.

Mounting the rigging flange
Mount the Rigging Flange Tim Barker

Position the rigging flange over the existing rigging hole on the boat. Use the flange as a template to mark and then drill three 1/8-inch holes. Take special care not to drill into any of the rigging behind the bulkhead. Bed the flange with marine silicone sealant, then install the part with No. 10 stainless-steel pan- or truss-head Phillips screws that are short enough that they don’t protrude inside and possibly damage parts of the rigging. Thread the rigging tube into the mouth of the newly installed rigging flange.

Installing the adapter and rigging
Install Adapter and Rigging Tim Barker

Make sure you have the adapter that fits your engine rigging port. You might need to obtain this part and instructions from the outboard company. Contact your outboard company to determine which one is correct. Each adapter secures differently. Once the adapter is installed, reinstall the lower pan, and reconnect all of the cables, wires, tubes and hoses. Reinstall the cowling. Connect the battery cables, and exercise the tilt and trim and steering to ensure the tube does not bind and that it isn’t excessively loose.

Installation with primer bulb
Making Room for a Primer Bulb Tim Barker

When there’s a fuel primer bulb between the engine and boat, a special rigging flange such as the T-H Marine Part No. RFFHP-1-DP provides a separate port for the fuel line, and the T-H Marine Rigging Flange Hose Union Part No. RFHU-1-DP, allows the fuel line to re-enter the rigging tube downstream of the primer bulb. The clamp-on hose union requires drilling a hole in the rigging tube for inserting the fuel hose; do this before any rigging components are inside the tube.

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