How to Install Side Mount Controls in a MerCruiser

Mercury Marine manufactures side mount controls for MerCruiser inboard-outboard drive systems. The controls consist of a trim box, operating handle and insulated cables with stainless steel fittings. A built-in safety switch prevents inadvertent engine start if the transmission is in gear. The controls mount on the sidewall of the boat near the skipper's station; you route the appropriate cables to the throttle linkage and transmission shifting arm. Side-mount controls are available through Mercury service centers and many marine accessory shops. The control package includes a template and all hardware necessary for installation.

Things You'll Need

  • Socket and ratchet
  • Open-end wrenches
  • Power drill or cordless drill
  • Assorted drill bits
  • Silicone adhesive
  • Duct tape
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Instructions

  1. Cable Connections

    • 1

      Remove the engine cover at the rear deck. Loosen and remove the nut at the top of the air cleaner with a socket and ratchet. Lift the air cleaner off the carburetor to provide clear access to the throttle linkage.

    • 2

      Place the control unit with attached cables on the edge of the deck near the skipper’s station. Although the controls mount on the sidewall at a convenient height, the precise forward/aft location is established after the cables are connected.

    • 3

      String the pair of cables from the controls along the edge of the deck toward the stern (back) of the boat. Insert the ends of the cables through the cable-port in the deck at the outer edge of the engine compartment. Reach below the deck and pull the ends of the cables into the engine compartment.

    • 4

      Position the coupler at the end of the red throttle cable alongside the throttle-linkage arm at the side of the carburetor. Feed the end of the black transmission cable through the circular port on the transom, or back wall of the hull. Position the coupler alongside the transmission shifting arm at the upper side of the outdrive.

    • 5

      Align the bolt port at the end of the throttle-cable coupler with the bolt port at the outer end of the carburetor throttle-linkage arm. Insert the provided shoulder bolt through the linkage arm from behind, and push it fully through the bolt port on the coupler.

    • 6

      Thread the provided nut onto the end of the bolt. Attach an open-end wrench on the head of the bolt as a backup as you tighten the nut with a socket and ratchet.

    • 7

      Position the stainless-steel throttle-cable stay alongside the flat metallic mount at the right of the carburetor. Align the port on the stay with the port on the mount. Attach the stay to the mount with the provided shoulder bolt and nut.

    • 8

      Repeat the cable connection procedure and connect the transmission cable to the transmission shifting arm on the outdrive with the provided bolt and nut. Attach the cable stay at the threaded port on the forward end of the outdrive with the provided bolt.

    Controls

    • 9

      Sit or stand at the skipper’s station as if driving the boat. Position the control unit against the sidewall of the boat at the preferred height with the handle pointing up.

    • 10

      Ask an assistant to hold the mid-portion of both cables against the inside of the hull, at least six inches above the deck. Mark an outline of the control unit on the sidewall.

    • 11

      Set up a power drill or cordless drill with the appropriate drill bit for the provided machine bolts that attach the controls. Use the provided template to mark and drill the holes.

    • 12

      Hold the controls in place as you insert the bolts through its face and fully though the sidewall. Reach behind the sidewall and put the provided washers and nuts on the ends of each bolt. Tighten the nuts securely with an open-end wrench.

    • 13

      Secure the mid-portion of both cables against the inside of the hull at two or more points with the provided cable ties and silicone adhesive. Press strips of duct tape over the cables and onto the hull at several places as temporary support. Allow the adhesive to cure before removing the tape.