On Mon, 4 Dec 2006 21:22:45 -0500, "Bill"
wrote:

I have a Kohler genset with a Yanmar 3G (H?)M. The problem we are seeing is
diesel fuel in the oil. It has less than 100 hours.
The fuel pump is electric. The engine starts and runs fine

It's most likely an injection issue of some sort. I have the 20 KW
unit and Kohler has an excellent parts and labor warranty on those
generators. I'd find your local dealer and give them a call.