I have a Kohler 11FZetc. I had the same issue as you until I discovered that it does not have an anode. If in doubt 'phone Western Marine Power (01752 408804). They are Kohler distributors and I am sure they will be able to help.
Hi Tom
I have the 5 or 6 EFOZ and I have an anode in the heat exchanger at the front bottom (not front bottom as in girlies particules!). I have a buddy with a small Yanmar engine (which is what Kohler Generators use) in his saily boat and he dont have an anode to replace...............so could be either !!
Best thing is like the other poster says have a look on western (or is it Advanced) Marine Powers website and they have manuals for their Gennys or give them a call to find out for sure. Best to treat it nicely coz, if its anything like mine, I reckon they would be a nightmare to remove
The manual does say front bottom for mine, it is fitted really tight against the main engine wet exhsust so hard to get in there but i did push a hand in and no anode?
Will have a second look tonight, I have just removed my engine anode and they are complety worn away so its needs doing.
Yes I will look after it since it keeps us warm charges the battries and lets us cook.