Could be. If the oil is not contaminated w/ fuel and it is pumping oil mist from the breather hose into the air box- it would be a likely scenario. So start with an analysis of what the oil looks like on the stick and go from there. IE hard to read, reads high, feels thin, smells of fuel etc. would be the signs of contaminated oil.

no gas smell in the oil. oil level good. it seems like oil is pumping directly into carb.

How adventurous do you feel? Service manuals are available from kohler at the low low price of free. I've not had a broken breather reed on these, but it is worth a look when you have the valve cover off. Below is a link. Use Internet Explorer and enter as guest.

Here is a link that might be useful: Kohler