I had that exact same problem on my 400DA's 7.6BTD. It ended up being the toggle switch in the generator's electrical terminal box. The vibration over the years broke the wire right at the switch potting. Insulation was intact so visually you'd never know. Just by accident I had my fingers in that box while it was running and it shut down; from there and wiggling wires I was able to find the culprit. Then another similar issue cropped up where the 12V circuit power wire in that connector by the Monoplex (10 Gauge wire) cooked the pin and socket in the connector and created an intermittent condition. That was easier to find due to the connector was discolored and a bit melted.

 

I had similar. Unplugging/replugging the harness connection fixed it for me.

 

didnt get parts ordered, but looks like a standard SPST switch. I'm going to get one from the Home Despot and try that to see if things improve.

I'm sure that diesel vibration takes its toll after a while...

 

We had a similar issue, sometimes it would run all day, sometime 15 minutes. Turned out to be the heat exchanger. Looked like plenty of water, but I guess not enough. Replaced and it was fixed.

 

The emergency shut down switch was the problem. As soon as I touched/wiggled it, I saw a little blue spark. Swapped out a new switch, and I’m back in business.

I couldn’t get the exact switch, but got one close enough that I think I’ve eliminated the random shut downs at least for the 4th week-end.

 

Hold the presses!!!

Generator ran great for about 5-6 hours then back to random shut down. Back to about shutting down about 15-20 minutes apart, maybe up to an hour.

seems electrical, but could also be a little air in the fuel???? I may check the small cartridge filter is installed correctly.

 

Still random shut down. It got to be one of the shutdown sensors, or the blower control module as it will also shut the generator down. Maybe a bad/loose connection or bad relay, or something in the fuel run solenoid.

I noticed that the Sea Ray Systems Monitor display showed “Generator Shutdown”, but I’m afraid this is only a symptom of the shutdown as I think it only monitors oil pressure. The alarm lags the shutdown by a second or two, so I don’t think any useful intel from the systems monitor.

im going to have to start jumpering sensors to see if one is bad. Any bets on what this is

 

Hey Dave - Did you pull this connector (circled in green) apart and look closely at it?

 

Hey Dave - Did you pull this connector (circled in green) apart and look closely at it?
View attachment 130132

No, but I’ll add that to the list.

 

Had a same issue, two different times, 1st time a loose wire in crimp fitting on a sensor, second time the return fuel line had deteriorated on the inside and was letting air in the system

 

Return line or feed line? I wouldn’t think the return line wouldn’t have any effect.

 

"im going to have to start jumpering sensors to see if one is bad. Any bets on what this is"
1. The one that is the most inaccessible
OR
2. The one that is the most expensive.

 

"im going to have to start jumpering sensors to see if one is bad. Any bets on what this is"
1. The one that is the most inaccessible
AND
2. The one that is the most expensive.

fixed it for you.

 

I didn’t think the return would cause a problem, but it did, the hose had like a plastic liner that was separating, letting air in an causing it to shutdown

 

I had similar. Unplugging/replugging the harness connection fixed it for me.

Did the plug have a zip tie on it to hold the two halves together?

 

It did not.

 

Looks like a bad exhaust temperature sensor. I jumped it out of the circuit and the genny ran happily all day. When I went to tighten up the screw terminals, one fell off into my hand, looks like the body was cracking due to age and vibration.

That temp sensor had never been mounted correctly with only 1 screw holding it in place. Additionally, it is mounted on the back side of the exhaust elbow making it very difficult to access, so I removed the entire exhaust elbow, and am going to rebuild it, and mount that sensor on the front of the elbow so future repairs are easier. Parts ordered.

One last issue.

When I separated the exhaust manifold from the exhaust elbow, the manifold sealing surface looks to be pitted/corroded. When I reinstall the new gasket, is there a gasketing material that would be acceptable to add to insure a good seal? I temporarily reinstalled the old gasket and it seems to be sealing fine, but...

 

Looks like a bad exhaust temperature sensor. I jumped it out of the circuit and the genny ran happily all day. When I went to tighten up the screw terminals, one fell off into my hand, looks like the body was cracking due to age and vibration.

That temp sensor had never been mounted correctly with only 1 screw holding it in place. Additionally, it is mounted on the back side of the exhaust elbow making it very difficult to access, so I removed the entire exhaust elbow, and am going to rebuild it, and mount that sensor on the front of the elbow so future repairs are easier. Parts ordered.

One last issue.

When I separated the exhaust manifold from the exhaust elbow, the manifold sealing surface looks to be pitted/corroded. When I reinstall the new gasket, is there a gasketing material that would be acceptable to add to insure a good seal? I temporarily reinstalled the old gasket and it seems to be sealing fine, but...
View attachment 130617

This one is their "Max Temp", a thin coating would be my suggestion.
https://www.autozone.com/sealants-g...TUOXnMCY3FCTIrzwxPHWSFIH8aDFWt5LnXCqLtY5V1-ZmxS-MJYJhoCDE8QAvD_BwE&gclsrc=aw.ds

 

Maybe some of this...

 

Maybe some of this...
View attachment 130618

There should be nothing high temperature on that genset except for the exhaust gas temperature.
First I would sandblast the area then fill with Permatex SteelWeld or JB Weld and machine down.
then go back with the OEM seal if any. Or, put a thin coating of that high temp silicone you are showing.

 

New exhaust temperature sensor installed and wired. Seems the gasket wasn't sealing very well. Added a bead of the high temp RTV and a new gasket.

Looks like the manifold will be in the schedule for this winter.

 

oh i'm glad i just read this thread. I'm at the boat warming the thing up and made some adjustments (mine was running about 3-4hz high under load) and was about to pull the elbow. I've decided that will likely wait until October now

 

Came across this in the Westerbeke Manual.

Proceedure on how to attach the exhaust elbow.

Cliff note version.

- Use a High Tack RTV on the manifold face ONLY.
- Torque clamp to 8-10 Lb-ft or 96-120 lb-in

 

Dave if you are still having issues with the exhaust, a short term fix can be use a flat file on both surfaces and then use a thin film of grease on the gasket if the gasket isn't metal on both sides.

Another approach is you can use Silkolene, that is for turbo sealing but works really well, also really expensive. If you use Silkolene then you don't have to use the file and can use the old gasket. That would be a temp fix until you can get the surfaces machined or replace them as needed. But I never use silicone on anything exhaust related.

https://www.silmid.com/us/sealants/...inting-compounds/762-high-temperature-jointing-compound-225gm-tube-was-renolit/

 

I got this back together last week, and I ran her hard for several hours yesterday, so the issue was an internal failure on the exhaust switch. I wish I had seen this before, as I added a small bead of High Temp RTV to both faces. Good news, its all sealed up tight, no detectable leaks.

However, I have a laundry list of things to fix on the genny slated for this winter, and as Tom suggested, refinishing the manifold face is on that list, So I should be able to do it to spec then.

 

Don't go and buy a tube of that incredibly expensive exhaust jointing compound. I've got an almost full tube of the Fuchs 762 Jointing Compound that you can use. I needed it for the V-band flanges on my turbo exhausts. So, if any of those joints are high temp you'll need it.

 

Lol! The high temp Permatex was $10!