I was mowing with my late model 140 with a Kohler K321. I noticed it started sounding funny. I raised the hood to see that oil was oozing out between the block and head (I also assume compression also under load is what I was hearing). This thing has eaten about 4 head gaskets in the last 15 years. The head has been replaced in an attempt to get a flat one, which did not cure the problem obviously.
Does anyone else have this problem? What gives? Engine does not run hot or lean. Even puffs a little black smoke under acceleration.