Kohler 9EFOZD generator

So, you are in a f/w lake ?

If in salt water then the salt water does not go thro the closed cooling system

I doubt the pump caused the issue of water in the.oil.




Regardless you need to lift the head first and check if you have a bent rod, if so, then the choice is yours, rebuild or replace.

If it's a wet exhaust and the electric raw water pump was operated for a period without the engine running it is very likely water backed up in the exhaust and flooded a cylinder or two and damaged some rings, a piston, or maybe bent a rod. That is why there are warnings for every wet exhaust system to NOT overcrank an engine that does not start.

also, that electric pump is not designed for raw water cooling application, usually they do not have enough capacity, even so, the pump should be interlocked so as not to run unless the fuel solenoid is in the run position, continuous cracking without flash up would potentially allow water back into the cyl head thro exhaust valves.

I think Marmot got it. To much water from the electric pump, filled the exhaust and into the cylinders.
Start the engine first and then turn the pump on.
That electric pump may also give to much water and over fill the muffler when running.
I think it's a current model 50htz gen set. Why the water modification for a late model gen-set?

I was told by the Jabsco rep that they do not make a 12 v pump sufficient to do Gen set cooling..however, I'm sure he is mistaken by the answers on here..so some other mfr must have that issue resolved..worth checking for future ref.

As several others have noted, there seems to be a problem with your terminology.

In a conventional heat exchanger cooled marine engine with wet exhaust, a raw water pump delivers seawater (or whatever floats the boat) to a jacket water (or fresh water coolant as some call it) heat exchanger. This heat exchanger uses raw water to remove heat from the coolant. The raw water pump can be driven by belts or an auxiliary gear drive but in the case of small engines is commonly belt driven.

After leaving the heat exchanger the raw water may pass through an exhaust manifold cooling jacket, before leaving the system through a spray ring located on an elbow usually connected directly to the outlet of the exhaust manifold. Here it is sprayed into the exhaust flow to cool and reduce the volume of hot exhaust gas.

Jacket water, fresh water, or coolant is a separate closed loop that is circulated by its own pump, usually driven by a belt on smaller engines just as on a car engine.

It is virtually unheard of for small diesels to use a separate pump for jacket water cooling.

It is not unheard of to install an electric raw water pump, but, in that case there is a great risk of the problem you have described unless operator proof interlocks are provided to prevent the pump operating before the engine is running or after it has stopped.

You use an AC powered pump powered off the Genset AC output. That way the pump only runs if the Genset is running.