Motorcycle Repair: charging, honda cb750k, oil temps

Question
I am restoring a 79 Honda cb750k Ltd. when i first start the bike up the charging system puts out 12.5 volts at idle at five grand i have 14 volts. after the bike runs at idle or two grand  warm-up the volts start to drop and at idle i will have 11 volts and falling. is it possible to have the stator or rotor fail when the engine is hot and be ok when it is cold? and what is a general temp. for the engine to be at sitting still at idle?

Answer
David, it depends on how long it's been sitting idling.  You can overheat an engine if it idles too long without moving.  It needs air over the engine to keep it cool.  It doesn't take a lot of air and a 20 inch window fan will keep it cool at idle.  Normal running temps are probably around 200 F oil temps.  

Regards
Rich