Have a Walker mower with a Kohler Triad OHC 16 engine. Used in a non-commercial application about 2 hours/week, with 162 hours on the meter. Checked the valve adjustment recently, and noticed the cam lobe which operates the fuel pump appears to have serious wear. So far, still chugging along. However, asked the dealer service department about this, and they said "it is not the best engine Walker has used." From early on have used Mobil 1 10-30 synthetic and changed it often, so it is doubtful this can be blamed on the oil. Anybody out there with experience on this powerplant? Suggestions for a replacement, if it comes to that? Or, possibly insufficient hardening on the cam lobe, and replace the camshaft only?