Saturday, 21 July 2018

Broken Throttle Cable Fix

After a run into an anchorage and before shutting the engine down I was clearing the water from the exhaust system with a couple of bursts of high engine revs. Then as I went to do the final burst the throttle leaver didn’t have any resistance, and the motor didn’t increase in revs. After shutting down the motor I discovered what the problem was.  The end had broken off the throttle cable at the swage connecting the threaded rod end to the internal cable.  Unfortunately the broken end was in the steering pedestal and adding the wire rope grips wasn’t going to work in the cramped location. I end for ended the cable and removed the stainless steel tube from the fitting head.  After adjusting the position of the end cable clamp and lining it up, I attached the wire rope grips. While the wire rope grips are not designed for this purpose they worked well. A final adjustment of the throttle cable to get the idle revs right was all that was needed. A simple and effective fix until we were able to source a new cable..

Broken Morse cable was jury rigged by removing stainless tube from head and using wire rope grips to hold end on

Why give the motor a couple of quick bursts to clear out the exhaust? In our case it will leave the exhaust system drier, if we have been at idle for a while it will stop a build-up of water running back down the exhaust pipe and flooding the engine. This really depends on the boat design, unlike most of the new builds, older vessels like ours (and others I know) have the motor below the water line so any exhaust water has to be lifted up and out higher than the motor.  If left to idle for several minutes it’s possible to partially fill the water lock and then once the motor is switched off, it doesn’t take much for a little water to run back down the exhaust pipe to push a little water up the exhaust into the motor. This is not a failure of the water mixing/injection elbow while this is a problem, sometimes this problem is misdiagnosed and a new elbow is fitted after clearing the motor of water.

No comments:

Post a Comment