Fixing the throttle cable

On the way from Mermaid Quay to Cardiff Yacht Club we noticed that we couldn’t get the engine out of idle. I guessed that the throttle cable had either broken or come adrift.

On Sunday morning we opened up the engine compartment and tried all the cables. It was quite easy to find the stop cable and check it was working, and the same with the gear control cable. That left the throttle cable identified as the remaining one and we could clearly see that nothing happened when we moved it.

So I started dismantling it.

The instructions for the remote unit were really clear about assembly so disassembly was straight forward at that end. There is a spring clip holding the out sheath in place and a nut holding the moving part in place. The nut is secured to the lever with a split pin which comes out easily if the lever is at the right angle. The nut was a bit corroded but just needed coaxing. Then it could be unscrewed. Below it is a locking nut and two rubber boots. Once these are removed the whole cable can be moved down and freed.

At the engine end there is is similar nut and split pin but the outer is connected to the engine block with two screws and a metal strap. One screw was quite accessible but the other one was fouled by the exhaust pipe. I managed to get the exhaust pipe off and then it was easy. Except as I removed the strap something plopped into the bilges.

I rummaged around with a magnet and miraculously found it. It is a straight plate which provides a stand-off from the engine for the control cable. I hope it isn’t essential because I dropped it again later and failed to find it.

As the cable came out one end fell off. Problem identified - the cable had sheared.

As I was extracting the cable Dave from Calypso came over. I explained the problem and he offered to drive me to Force 4 to buy a new one. This helped enormously. The cables come in set lengths and the shortest was 6’. At least a foot longer than our old one but I bought it.

Reassembly was really easy except for that strap on the engine block. The extra length of the new cable was fine.

The only thing to remember at the remote control end is that the locking screw and rubber boots need to be removed and put on in the right place. The boots come in place but not in position. Once removed the cable is threaded into the unit and the lower boot fitted between two parts of the unit and pushed over the outer sheath to stop dust getting in. The upper boot does a similar job for the cable itself. The lock nut goes on below the main nut and is tightened to it once everything is in place.

Back to the engine end. The strap has a ridge which fits in a groove on the cable, stopping it sliding backwards or forwards. The cable is sandwiched between the strap and a flat piece of steel and two screws hold it onto the engine block. I managed to drop the flat piece into the bilges. I put everything together without it and it seems fine.

Once the outer cable is locked in place it is clear that the nut needs adjusting to exactly fit into its hole. Then the final split pin can be fitted and the job is done!