In case others come across this thread like I did.
I ran across this thread because I had heat issues with my new polisher. Turns out it was that I didn't put the little plastic washer between the backing pad and the buffer. The screws on the backing bad were pressing against the counterweight and causing it to not spin freely. it oscilated, but did not spin. Once I put the washer in place the buffer works fantastic! A great machine.