I have two identical LGT 145s with 14HP Kohler engines. Mower number 1, which I have owned for about 8 years, ran fine until about a year ago when it would die after 15-20 min running. Tried everything fuel and electrical but no success, so finally gave up and bought mower number 2. That ran fine all last summer until the end of the season when it became very hard to start. In a previous post, I detailed what I found wrong with the head and head gasket and after having that corrected, the mower now seems to be back to normal.
So now I'm looking again at mower number 1 to hopefully get it running again. Pulled the head today and the pictures show what I found. The exhaust valve is a strange brownish yellow with that same color on the block adjacent to the valve. There is some oil on the block and head gasket toward the front. As the piston sits in the bore, it is almost touching the bore toward the front but there is about 1/16" gap around the other side. None of this looks good to me. Could any of this be causing my lack of power and eventual dying of the engine?