Kohler Generators

J

jasontbrant

New Member
Jul 8, 2010
55
Chesapeake Bay and tributaries
Boat Info
280 Sundancer 2004
Engines
Twin 4.3
I have a 2004 Sea Ray 280 Sundancer with a 5Kw Kohler Generator. I have been experiencing an issue where the generator will turn on and operate normally for 5 to 10 minute before shutting itself off. I replaced the impeller recently and have fantastic water flow. I verified that the fluid levels are correct. The oil pressure is where it needs to be as well. The only thing that I have found is that the cylinder head and heat exchanger seem to be running at about 230 degrees according to a heat gun. I cannot figure this out and was hoping that someone on this website would be able to help!!
 
Some problem here and I plan on changing the impeller tonight. Couple of questions:

- You have good water flow, but is it hot?
- When you changed the impeller, was it in one piece? Could it be that you have some pieces of the old impeller stuck inside?
- If you have a Control Panel, what fault code do you get?
 
I haven't checked the temperature of the discharged water but will do so tomorrow. The impeller was missing two vanes which I were located and removed. I don't believe that I have any codes at the helm but will double check tomorrow.
 
I think fell4it meant the codes on the control panel located on the generator (not at the helm). But, since your is 2004 I don't think it had digital board on the genny.

I would dbl check the water flow. If this is the first time you replaced the impeller, then it's always possible that there could be more stuff creating blockage (older vanes, marine growth, etc.).

How about the fuel side? Was the spark plug and fuel filter changed?
 
A friend had this same problem. Good water flow out the of exhaust but the water coming out the exhaust was cood.The closed cooling system portion of the heat exchanger is very sensitive to a low level. Slightly low and the antifreeze will not flow through the engine and heat exchanger. Even though the antifreeze looks full you must pull the vent/bleeder plug on top of the heat exchanger casting when filling.
 
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Just because you have good water flow doesn't mean there is not a clog. Stick your hand in the exhaust. Be careful. A small clog can make the exhaust water very hot. If it is more than lukewarm. There is a clog somewhere between the exhaust and the seacock.
 
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It sounds like step one will be for me to check the exhaust water tomorrow. In the interest of full disclousre, there have been a few trips where I started the generator, let it shut itself off after a few minutes, repeated three or four times and then found that it would run uninteruppted through the night.
 
Has the generator been used all winter or was it winterized? How was the fuel system winterized? I've had the same issue and it was indeed fuel related.
 
This motor has two cylinders while running feel the top on the exhaust ports see if one is hotter than the other. I worked on a friend of mine and one water ports was plugged up on the exhaust side and was doing what you described.
 
I had a similar problem but it quit sooner, it ended up being the gas filter.
 
The water is not hot leaving the boat. The impeller was missing two fins but they were found. The next step is for me to look at the control panel, but I will have to unbolt the generator and slide it out since it is on the side facing in.
 
Ahhh, I've had this very issue! Same symptoms, same temperatures. What you have is an air pocket in the closed cooling system. Have you recently flushed and re-filled the coolant?

That is what I did. I thought I got it filled up properly. But it would shut off after 5-10 minutes and my temp gun would show high temperatures. Had nothing to do with the impeller and water flow.

There is a little pipe plug that is on the forward top side of the generator (towards the bow). If I recall, it's straight back from the radiator-style fill cap. You need to remove this pipe plug and then top off the coolant from the fill cap, until coolant flows from this pipe plug. Then replace it and continue to fill until topped off. Make sure your overflow bottle is about half-full (on the port side of the generator).

You may have to do this a couple of times, waiting for it to cool before opening the cap and pipe plug each time. I had to put in about 12 ounces or so on the first go and that was all it took to fix the problem. I was alarmed at how large of of an air pocket there was that was trapped in there due to the flush and fill.

Tom
 
Unfortunately, I confirmed that the tricks shared to eliminate air pockets in the coolant were unsuccessful. I have enlisted the help of a mechanic who said the easiest way to get at everything is to move the fresh water tank. He believes that the coolant sensor is grounding out and sending a signal to shutdown the system or the thermostat is not opening. The sensor and thermostat are now on order and I will keep everyone posted on the outcome. I appreciate the time, advice and assistance you have all provided!
 
Did you confirm good water flow from the seacock to the impeller? This can also cause problems. That would cause your impeller to fail prematurely.
 
jasontbrant said:
I have a 2004 Sea Ray 280 Sundancer with a 5Kw Kohler Generator. I have been experiencing an issue where the generator will turn on and operate normally for 5 to 10 minute before shutting itself off. I replaced the impeller recently and have fantastic water flow. I verified that the fluid levels are correct. The oil pressure is where it needs to be as well. The only thing that I have found is that the cylinder head and heat exchanger seem to be running at about 230 degrees according to a heat gun. I cannot figure this out and was hoping that someone on this website would be able to help!!
Click to expand...


Check your water strainer? I have been having intermittent surging/stalling problems... have checked everything under the sun (or so I thought), but missed the obvious until Sunday night. Changed nearly everything on the genrator (plugs & fluids), but never thought about the water strainer until I stubbed my toe on it. Had too much focus on the generator itself I guess. Of course, took the cap off and here are two big leaves in the filter basekt, sort of trapped down at the bottom. Im betting (praying) that these puppies get swirling around occaionally, leading to random blocking/reduction in water flow, and then surging/stalling due to nearing overheat. If that's not it, it's time for the repair techs to visit. Will know more tonight after I head over to the boat and run it for a while off the lift.
 
I have now had two different and well respected mechanics on the boat and neither was able to identify or fix the problem. I am now awaiting a visit from the local Kohler representative...which should be interesting. I am happy a manufacturer representative will be visiting but I cannot believe it is July and I have been without a generator since commissioning at the end of April.
 
That really stinks. I hate to suggest it again, but I would spend some time working as if you had air in the closed cooling system. Wont cost anything and your symptoms still don't rule it out since no one was able to find anything mechanically wrong with it. That's what was wrong with mine. Frustrating I know...

Good luck!
 
My mechanic had someone from Kohler on the boat and texted me this morning saying it was a defective temperature switch. Apparently it works now but I still need to go see it for myself.
 
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