Generator load questions for the resident panel


Jeyzuss kid…such impudence! Mind your mouth when referring to your elders

I haven’t done shit to fix anything yet…when the one gen was going through its cycling, I switched over to the opposite genset which I already had running. The cycling stopped, I let the batteries recover a bit of their charge and then started the mains. The one gen with the problems was simply shut down and I came on here to ask what the issues with it could be.


One last, has this genset ever run smoothly when taking on a load.


yes, it was the generator I would usually start when lighting up the vessel. always had been steady and smooth previously.


Hmm. . . that would seem to discount the droop setting, unless it somehow vibrated to a different position. . . could still be the governor. . .


As everyone has suggested start with the easy stuff first. Before starting the engine, work the fuel rack back and forth to make sure it wasn’t sticking from sitting idle.


Funny how folks complain about company owners not spending money on their vessels to keep them safe, functional, etc…

But when it’s your own money, and having to spend it on your own vessel, straight to the internet to find the problem! :smile:


+1 for checking the rack linkage. Pull the valve cover and check that the individual injector racks are free.


no, I have verified that the rack is free to move throughout its range


@c.captain, reading your post made me wonder about whether you are using the start batteries to supply voltage to the Governors also. If you can try to isolate the power feeding the governors from the starting circuits. You should be able to use a 12/24 volt setup (depending on voltage required for the Governor) temporarily just to see if the problem goes away.


I’m thinkin’ I’d pull the valve cover, start it up and watch the rack… If it bogs down with full rack I’d look at fuel supply issues. If it bogs down with the rack moving towards fuel off I’d look at governor/control issues. Had an 8V 71 once that idled at about 1200 turns, and wouldn’t shut off. Turned out one of the rack clamps slipped, it was running on one cylinder… Flir camera or IR gun is a quick way to check that kind of thing. Also, Jimmy’s gonna sling less oil when he’s cold. Good luck.


Speaking as an Unlimited Engineer as well as a 200 ton Master, I suggest you:

  1. Change the primary fuel filter. It’s always always always the first thing you do to a Detroit. Doesn’t matter if you changed it yesterday, change it again.
  2. Install a pressure gauge on an unused pressure port on the secondary. The presence of a pressure gauge gives you so much troubleshooting information I’m surprised they don’t come that way. Always the first thing I do when I get to a new boat with Detroits is install that gauge on every engine. That gauge will give you such a wealth of information, and every Detroit mechanic worth a lick will have one in his toolbag.
  3. Stop fiddling with it. I agree that it could be sticky flyweights in the governor. It could be a sticky (or stuck) injector, it could be that the droop adjustment is out of whack, it could be a lot of things in the governor. I suggest that if you decide to take a valve cover off or the governor cover off that you have just made a significant Captain error thinking that you might know what you are looking at. In every corner of every boatyard and diesel shop in the United States is some old guy (and a few young ones) that have been working on Detroits for 30 years, and actually know what they are looking at. They are worth the 200 bucks you will pay them to come peer into your inner workings and give you an A-ha moment. When you get there, you will, of course, never have that problem again, but a different one.
  4. DeepSeaDiver is giving you good advice. You can choose to follow it or not, just like any advice you get here. But his troubleshooting guide is right out of the Detroit manual. It is based on millions of hours troubleshooting Detroits. Fuel lines do collapse inside, or more often peel a flap away that exhibits exactly the symptoms you describe, I’ve also seen the racor check balls stick, and the racor suck air up the drain, a hundred things that a mechanic will figure out in 15 minutes.
    Best of luck to you. Having chased these problems as a crewboat owner, captain, and OSV Chief, I know that the issues are legion.


Thanks to all (including DSD) for the many suggesions. I will go back aboard Saturday ready to start working through the possible causes. Should not take long to isolate the problem.


so as stated previously, made it aboard the DAUNTLESS again today to try to isolate the issue with the port genset. this time started it as always at low RPM and allowed it to warm a little before dialing it up to 1800 and closed the breaker with no loads on the buss. This part always was never a problem and this time, I started to add load on the generator by using the galley range. Nothing happened to the gen with only a burner so lit up the entire range and still no problem with the generator maintaining rpms. Pretty soon I was adding loads everywhere I could and still no problems. Closed the breaker to the battery charger and then went to start a main (which before was the beginning of the cycling issue) and even with the charger putting out 80amps the genset just kept on going as before with it putting out 20kW of the 45 it is rated for. Never once lost rpms and when adding loads only a slight change in its sound as the loads hit it.

so now I have no clue as to what was causing all the trouble last weekend but the problem is now gone (at least for the time being) and will just wait to see what happens the next time.


Sounds like everyones thoughts and prayers did the trick.


Prayers? must have been for the generator because I know no one prays for me…including my own mother!


Probably the rack rod sticking on one of the injectors. Normally happens after it’s dormant for a while. I’d still pull the valve cover, inspect and actuate the linkage.


I’ve had engines that were supplied with JUST ENOUGH fuel to be fine but just a LITTLE MORE load resulted in fuel starvation. Only a press guage would detect this and it sometimes took a bit before it’d start to lose rpm.
You probably won’t see it happen again till you’re underway !!!


I solved a problem like that by getting a fuel pressure gauge installed at the helm. The issue would only arise at high power settings after some hours, you would never see it at the dock.


Glad it worked out. We have all experienced PFM at times


drain your day tank see if that works