Motors fitted and ready to go

Swapping the motors on Seahorse

Motors fitted and ready to go
Motors fitted and ready to go

After making the decision to do so, replacing the two 90 horsepower two stroke engines on our boat with smaller and more fuel efficient four stroke engines took a fair amount of time. The task was loaded with extras such as rewiring the console, navigation lights and instruments, as the existing wiring was a little shabby. I also wanted to replace the fuel lines from the tank to the filter. To fit new control cables, control box wiring and battery cables, the deck section behind the console had to come out. While it was out it seemed pointless not getting everything changed at the same time. I also discovered that the clearance between the bottom of the console and the top of the tank was insufficient for the huge plugs on the new wiring looms so I had to lift the console as well.

Removing and replacing the actual motors went relatively quickly and by early afternoon both motors were fitted and the hydraulic steering connected and bled. The rest of the work is all far more time consuming but a lot less strenuous. Installing new control cables and the new wiring looms from the control boxes went well. I also ran new power cables from the batteries up to the console and rewired everything in the console. I split the console switch panel in two, so half the switches were powered from the port battery and the other half from the starboard battery. I also split the bilge pumps’ wiring so each battery has a pump connected to it. The tachometer, hour meter and navigation light wiring was already there but the wiring was not in great condition so I removed it all and made up a new loom.

Seahorse at the jetty in Simon's Town
Seahorse at the jetty in Simon’s Town

Coaxing cable and wiring under the deck is always a relatively slow process as there are existing sensitive cables such as the sonar transducer cable and VHF antennae cable going through the same holes.

The boat is also fitted with two electric bilge pumps, one is switched and one on permanent auto so these were also rewired.

Once the cables and looms were in place the motor loom plugs were attached to the engines’ new battery terminals and new fuel hoses and fuel were bulbs fitted. Propellers were next and suddenly, it was all done. Ready to start. The sound of a quiet four stroke running in the driveway as opposed to the noise the two strokes made will certainly endear me more readily to my neighbours!

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Scuba diver, teacher, gadget man, racing driver, boat skipper, photographer, and collector of stray animals