Caterpillar 3116 engine. Machine would not turn over one morning, troubleshoot and found a burnt wire on solenod, remove starter and found starter motor windings burnt internally, figured something caused power to remain on starter and burnt it up, re-wired all suspect wiring and installed new starter -- started fine, worked machine 4-5 hours, shut down for 15 minutes, would not turn over, nothing, starter felt hot to touch -- hour later starter cool -- started right up -- worked it 1 hour -- shut down and tried to start it back -- nothing -- same story -- soon as starter cooled machine cranked. I am building a heat shield for the starter to protect it from the exhaust heat but the main question I have is why did this start happening now? this is a 20 year old machine and the same style starter has always been in the same location without a heat shield, I ordered the starter through a highly reputable and experienced starter and alternator shop but I guess there could be a difference in internal insulation or design as compared to the OEM.