I had replaced the original mechanical voltage regulator with an electronic one about five years ago. 2000 rpm is not high idle but the recommended working rpm for the 23 hp two cylinder diesel so it needs to be charging well at that level. The battery checks 13.09 volts engine off. I'll see what the reading jumps to this week end. I'm also going to take my VOM in and get it checked as it is 25 years old. Thanks