Shifty, Shifty – Replacing Morse Control Cables

We had taken a cruise around the Chesapeake Bay and everything on Lux was working as it should. But as we were coming back to our dock, we discovered that the starboard engine throttle didn't work. After a few minutes of diagnosis, we discovered that the throttle cable had broken. Without throttle, we had limited engine thrust at idle speed. At least we could shift gears.

It’s finally time to replace the Morse control cables. The starboard engine shifter and throttle had not exhibited any stiffness, so it was interesting that the cable broke. The port shifter however, was stiff and we were apprehensive about replacing the long cables that needed to go through two conduits and several bends. It turned out to be easier than we anticipated.

What length should we order? We could remove the cables and measure them, but then we wouldn’t be able to use the old cable to pull the new cable through the twisty passages.

Internet research indicated that the cables should have a number stamped on them. Sure enough, we found numbers on the cables after removing the Morse shifter mechanism at the helm: TFX 032377-03 360.0 Further investigation on the Internet found that the last number, 360.0, is the length in inches. Blue tape labels were added to identify the cable functions: shifter, throttle, and stop. The cables were confirmed with Leopard Catamarans as model 33C (alternatively labeled 3300CC):

• Starboard shifter 21 ft (6.5m)

• Starboard throttle 21 ft (6.5m)

• Starboard stop 25ft (7.75m)

• Port shifter 27ft (8.5m)

• Port throttle 30ft (9.5m)

• Port stop         30ft (9.5m)

Replacement cables were ordered from Jamestown Distributors. They are reasonably priced and when they arrived, we found a significant improvement in the smoothness of operation. That was what many of the online posts had said, but it was nice to find out that it was true.

It is also easy to find the mechanical drawings for the Morse Control online (dual control in our case). Disassembly is straight forward. The picture below shows the starboard half of the shifter with the new black-covered cables in place. The red cables are original and go to the port engine. 

The next picture shows the internals of the shifter mechanism. Four screws hold the dual assembly into the fiberglass and two machine screws hold the two halves together. Note the extensive use of grease to keep corrosion at bay.

Installing the new cables

On the 2005 L40, running cables from the controls to the engines is pretty easy. They go down to the space behind the starboard-aft cabin access panel. The starboard cables then go into a blue conduit that connects to the engine compartment. Leave enough slack at the helm shifter to allow for servicing.

The cables to the port engine take a longer path through conduit across the bridge deck, then into another blue conduit that goes aft to the engine compartment. We found that it was easiest to use the old cable to pull the new cable. We removed the nuts from the cable ends and coupled the two cables together with a 1 ft long piece of duct tape wrapped lengthwise. The fibers in the duct tape provide strength while allowing flexibility. One person can pull the new cable in place if you don’t mind going back and forth from end to end. It was best to pull all the cable into the area behind the panel in the starboard aft cabin, then pull it into the area behind the port aft cabin, then into the port engine compartment.

During the process, we found a one of the port engine cables had a 2-ft diameter loop behind the electrical panel in the port-aft cabin. We eliminated this loop during the installation of the new cables, which helps make the operation smoother.

The ends of the cables are setup the same as with the original cables, so take pictures of the connections before disassembling them.

We’ve not had to replace the engine stop controls. The starboard stop cable can be installed by hand after removing the old cable. Either pull a pull-cord in place or cut off the helm end of the stop cable and use duct tape as with the shifter/throttle.

We had to spend a little time adjusting the linkages so that the throttle handles were even with each other at the same RPM. That’s no big deal.

Alternatives

You may find articles that describe dripping oil into the control cables. We did this initially. It was a waste of time. The amount of time we spent trying to lubricate the cables was comparable to the time to replace them and the results were not as good as the replacement.

Results

We found a significant improvement in shifting and throttle operation after installing the new cables. The installation wasn’t as challenging as we had initially anticipated. One of us was able to do the entire job unassisted. The starboard engine controls took about an hour to replace while the port engine controls took about three hours.