Recently my Westerbeke 10/2 diesel has been experiencing something strange. The rpms go down a little (maybe 200 or 300) for a few seconds. At the same time, the voltmeter goes all the way to the highest reading. When the rpm returns to the previous speed, the voltmeter goes back to normal. The worst part is that the periods of this are getting longer - up to almost a minute at a time. A friend thinks maybe water in the fuel might cause the rpms to go down, but I am wondering if the alternator is going???
engine rpm problem
- Thread starter Dream Weaver
- Start date
Sounds like your voltage regulator is going wonky. It takes horsepower to make volts/ amperes. When the regulator calls for more, the rpm will drop a little. Check alternator connections first, including ground. A local shop can usually rebuild pretty cheaply.
Hit it right
I think kloudie nailed it. Your voltage regulator is screwing up and allowing the alternator to go full charge. 200 or 300 RPM sounds about what it would pull a smaller engine down.
I think kloudie nailed it. Your voltage regulator is screwing up and allowing the alternator to go full charge. 200 or 300 RPM sounds about what it would pull a smaller engine down.
Could be the regulator.. What is the actual voltage when the engine dips? I also think something on the boat is requiring power (amps). A voltage regulator can go over voltage but it cannot shove power (amps) into the system..something has to require it. And 200-300 rpm is about right for a small engine but it takes power to drag it down (amps/voltage). are the batts getting hot? I'd check both.