Kohler 6.5 fouls plugs after 30 minutes...

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Greetings,
Mr. 91. Simple solution for indicator of generator operation might be to wire a 110v LED into a fixture normally on and powered by generator. Small mounting hole in the faceplate of or directly beside an outlet perhaps?


https://www.ebay.ca/itm/PL1601G-ATI...ash=item33c8378104:g:cOAAAOSwA3dYmk6G&vxp=mtr


s-l225.jpg
 
One more question. When running the generator when not moving, the exhaust exits out the small hole on the side of the boat. When underway, nothing comes out at all. Is it exiting through the main engine exhaust? Is that small hole just a secondary exhaust when stopped?

What stinks is when underway, you can’t hear the generator so you can’t tell if it’s still running. And we have no gauges at all. The only indication is to flip something on like the outlets and see if they work.


That exhaust outlet should be the only one, you may not be seeing it at speed because it has a lift muffler more than likely and surges exhaust and water as pressure builds enough to release, be sure to watch it for a couple seconds. If you aren't seeing any water at all while underway I would find out why, sounds like you could have a problem. The gen. will (should) shut down with an overheat alarm if you lose raw water but I would be looking for an issue if you truly don't have any water/exhaust flow while underway.
 
That exhaust outlet should be the only one, you may not be seeing it at speed because it has a lift muffler more than likely and surges exhaust and water as pressure builds enough to release, be sure to watch it for a couple seconds. If you aren't seeing any water at all while underway I would find out why, sounds like you could have a problem. The gen. will (should) shut down with an overheat alarm if you lose raw water but I would be looking for an issue if you truly don't have any water/exhaust flow while underway.

Yeah I watched it for a while and it was bone dry. I’ve noticed it before as well. But it ran for hours. If it had a cooling issue it would half presented itself.
 
Yeah I watched it for a while and it was bone dry. I’ve noticed it before as well. But it ran for hours. If it had a cooling issue it would half presented itself.


You had water running (surging and gurgling) at rest from the gen., but not underway??
 
You had water running (surging and gurgling) at rest from the gen., but not underway??

That’s correct. I had actually thought it had shut down when I looked at the exhaust outet while under way but the AC was still on. There was no sign of water or anything coming out of the exhaust.

I’m wondering if it exits into the main’s exhaust. Maybe when the main is under a load it will help pull the exhaust and water from the generator? It when there’s no load it has a secondary outlet that’s the one I was looking at? Idk, I’m guessing here. On Sunday I’m going to the boat to do some work. I’ll follow the exhaust for the generator and see where it goes. I know the main exhaust goes into a large canaster muffler. Maybe the generator Y’s into it.
 
That’s correct. I had actually thought it had shut down when I looked at the exhaust outet while under way but the AC was still on. There was no sign of water or anything coming out of the exhaust.

I’m wondering if it exits into the main’s exhaust. Maybe when the main is under a load it will help pull the exhaust and water from the generator? It when there’s no load it has a secondary outlet that’s the one I was looking at? Idk, I’m guessing here. On Sunday I’m going to the boat to do some work. I’ll follow the exhaust for the generator and see where it goes. I know the main exhaust goes into a large canaster muffler. Maybe the generator Y’s into it.


It only has one exhaust, should be a lift muffler with about 1.5" to 1.75" hard wall exhuast hose out the hull after the lift muffler, possible to have an in-line muffler with a goose neck at the hull as well. I can't imagine any scenario ever where they would tee into the main engine exhaust. Only other possibility would be no water pick up when boat on plane but no manufacturer would plumb that way so if it was done after the fact and someone put the raw water thru hull closer to the middle of the hull that is out of the water on plane. That's a very unlikely scenario and would cause gen to overheat in a matter of minutes anyway.
 
It only has one exhaust, should be a lift muffler with about 1.5" to 1.75" hard wall exhuast hose out the hull after the lift muffler, possible to have an in-line muffler with a goose neck at the hull as well. I can't imagine any scenario ever where they would tee into the main engine exhaust. Only other possibility would be no water pick up when boat on plane but no manufacturer would plumb that way so if it was done after the fact and someone put the raw water thru hull closer to the middle of the hull that is out of the water on plane. That's a very unlikely scenario and would cause gen to overheat in a matter of minutes anyway.

The pick up is near the main engine pick ups. And when I say when underway, I mean 7 kts.

Yeah I don’t know. I’ll have to check it out this weekend.
 
The pick up is near the main engine pick ups. And when I say when underway, I mean 7 kts.

Yeah I don’t know. I’ll have to check it out this weekend.


Oh, well definitely not a water pick up issue from plane then. Bizarre, let us know what you find out, cheers.
 
It could have a Exhaust/Water separator.
 
It could have a Exhaust/Water separator.

That only works when the boat is underway?

Idk, this is odd. Obviously the generator would shut down or overheat and melt if it had a cooling problem.

So in this video, at 1:12 I start the generator and at 3:00 I walk around to the port side on the docks. You can see the main engine exhaust and just in front of the bumper you can see the water spitting out of the generator.

https://youtu.be/1D__9JFzD_I
 
Update! Took the boat to get breakfast. When we were done and going to head back I fired up the generator to get the AC going. It started right up and held the load beautifully. No surging. I’m thrilled. Can’t believe it was just those little O rings.

Also I solved the mystery of no cooling water while underway. Turns out I’m an idiot. While cruising at 7 kts, the generator exhaust is underwater and not visible. I thought I was looking at the exhaust outlet, but I was just looking at another drain. Little embarrassing. Oh well. I’ve done worse.

Anyway, thanks to everyone who helped me get this thing running!
 
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