My Kohler 7.5kw, gas, genset runs for about 20 seconds then shuts down and throws an over-heat fault. The Kohler tech replaced the impeller because it was in pieces. After that it ran fine while he was testing it but when I tried it a couple of weeks later it started doing the same thing - starting up fine but it wouldn't prime then would shut down and throw an over heat fault. Anybody ever have a similar problem? Cheers
If its not picking up a prime you have an air leak prior to the pump. I would also clean out the heat exchanger to make sure you get all of the impeller pieces.
I wouldn't think anything would get hot enough to overheat in 20 seconds. Makes me wonder if there is a bad temp sensor. Most newer gen sets I've messed with, it takes about that long for the system to come online, then it would catch the faulty sensor and shut down.
I'm new to all of this stuff. My SkipJack 25 didn't have all of the systems that the larger boats have. It's still under warrantee but it takes so long to get these guys out. I've been trying to learn how to work on the different systems. The Kohler manual is terrible. Anyways thanks for the suggestions. Cheers!
if it trips in 20 seconds there is a chance you have a loose connection somewhere in the temp sensor switch circuit.
I agree with Some Texan. It does sound like a faulty temp sensor. I replaced the one on my Kohler 7.5 with a comparable sensor from an auto parts jobber. I can't remember the trip setting but it works fine and has for several years. Try that. Sometimes it is the cheapest repair that works...even on a boat.