Leak in generator

Team PCBeach

Active Member
Oct 12, 2010
183
Boat Info
360 Sundancer 2003, SIMRAD 3G Radar, Raymarine Autopilot
Engines
Twin 8.1L Horizon
7.3KW Kohler, ran fine two trips ago last trip started up and ran for 10 seconds and then died. Won't restart. Acts like no fuel or spark. Removed sound shield to make sure was not low oil and oil was fine, but found what I think is a coolant leak. Looks like a very slow drip at the heat exchanger. Is this just an easy gasket change out? I know this probably has nothing to do with the starting issue but still need to address it. I will also take any suggestions on troubleshooting the starting problem.

generator.jpg
 
7.3KW Kohler, ran fine two trips ago last trip started up and ran for 10 seconds and then died. Won't restart. Acts like no fuel or spark. Removed sound shield to make sure was not low oil and oil was fine, but found what I think is a coolant leak. Looks like a very slow drip at the heat exchanger. Is this just an easy gasket change out? I know this probably has nothing to do with the starting issue but still need to address it. I will also take any suggestions on troubleshooting the starting problem.

View attachment 100504
Looks like you got the source correct. To take a look inside, you have four bolts on the front and rear flange. The lower rear bolt is no bueno...a gigantic hassle. You will understand once you get there. The front flange has a thermostat in it. No gasket but an o-ring in both flanges. If you just loosen all four bolts, you can get a look at things and see if you can just reseat the thermostat and check to be sure the o-rings are seated properly and tighten her back up. Might get lucky. If you need to replace the o-rings or thermostat...

Heat Exchanger O-Ring | Kohler 359319 (marinepartssource.com)

Generator Thermostat | Kohler 249930 (marinepartssource.com)

EDIT - I just looked back at your photo and realize you have an older version of the 7.3, so don't trust my part numbers above. Be sure.
 
I will also take any suggestions on troubleshooting the starting problem.View attachment 100504
You have it harder than I did on my 7.3 as I have the newer controller with the LCD that displays a fault code. That said, it isn't likely a coolant issue as 10 seconds isn't enough time for unit to overheat. On my troubleshooting journey, the issues were a failed CO sensor (but I don't think the older version has one), then a failed SCR Module. I also replaced all the fuses just to be sure since they are so cheap. The fault code I'd keep throwing on the 10 second shutdowns was voltage related, so you're likely looking at troubleshooting wiring, relays, fuses, etc.

I also had a slightly longer run before shutdown that was due to a few impeller fins that had become lodged in various places (one right by the raw water pump and one in the high pressure fuel pump). It took me several round of go back and try something new to work through them all.

You can always replace your plugs. That's pretty easy. Also, there is a fuel bleed valve between the fuel pump and the injector on top of the unit which you can press in and then do a startup...you'll make a small mess, but you'll know if your fuel pump is working when fuel sprays out of the valve.
 
There's a bunch of stuff it could be. Find your manual and do some good trouble shooting.

A bad oil pressure sensor will do the 10 second shutdown.

If your unit will stay running while the start button is pushed I'd bet it's a bad sensor somewhere.
 
Thanks for all the tips, will take a look next time I am at the boat. I am not sure I was clear in my first message. After I had the 10 second shutdown, the generator will now not start at all, even with the start switch held down.
 
Thanks for all the tips, will take a look next time I am at the boat. I am not sure I was clear in my first message. After I had the 10 second shutdown, the generator will now not start at all, even with the start switch held down.
But it tries? Turns over but never fires up? I'd check the fuel pump, maybe the injector is clogged? The voltage issues only presented on mine after at least a short fire up. It would fire for a second or two and then fault with a UU code.
 
@Atalla yes it tries but never fires. I hope to get to the boat this week. First task will be to tackle the coolant leak since it doesn't matter if I get it to run and the coolant leaks. Then I will move on to the no start. Will check your tip on the fuel bleed valve first to see if I am getting fuel. If so, will move on to the plugs.
 
Got the coolant leak fixed. Thanks @Atalla for the links to the parts! Found a great 3 minute video that did this exact job (
).

As you said the back lower bolt sucked. But being 6' 4" 260lb doing anything in the engine compartment of a 360 Sundancer sucks.

Unfortunately I still can't get it to start. Oil is good, coolant is good, fuel pump pumps fuel when start switch is held, and put new plugs in. Still cranks, but no start. Wish I had a newer unit that had the display with fault codes. Tomorrow I will pull the fuel line at the carb to make sure there is flow there, but I expect it to be good. About out of ideas.
 
Got the coolant leak fixed. Thanks @Atalla for the links to the parts! Found a great 3 minute video that did this exact job (
).

As you said the back lower bolt sucked. But being 6' 4" 260lb doing anything in the engine compartment of a 360 Sundancer sucks.

Unfortunately I still can't get it to start. Oil is good, coolant is good, fuel pump pumps fuel when start switch is held, and put new plugs in. Still cranks, but no start. Wish I had a newer unit that had the display with fault codes. Tomorrow I will pull the fuel line at the carb to make sure there is flow there, but I expect it to be good. About out of ideas.
Glad it helped but sorry you still don't have it running. Injector could be gummed up. Easy to replace if so.

It is only cranking...no sign of life? Gotta be fuel right? Not giving it a chance for all the other crap to fail.
 
I am guessing fuel. Mine is from 2003 and is has a carb, no injectors. Next test is going to be trying some starter fluid.
 

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