Motorcycle Repair: CHARGING PROBLEMS, ac volts, motorcycle shop

Question
MOTORCYCLE SHOP TOLD ME TO CHECK THE AC VOLTS WITH THE BIKE STARTED AND THE RPMS AT 5000. I CHECKED THE PLUG THAT HOOKS UP TO THE STATOR(THE FEMALE END)IT ONLY READING 54 AT 5000 RPM'S. WHEN THE BATTERY IS FULLY CHARGED I GET ABOUT 1-1 1/2 OF RIDING THEN IT JUST DIES. I THEN READ THE VOLTS AND IT IS UNDER 9 OR SO. IF I LET IT SIT ABOUT AN HOUR IT GOES BACK UP TO ABOUT 10-11. IF YOU OR SOMEONE CAN ANSWER THIS QUESTION IT WOULD BE A BIG STEP TO GETTING THIS PROBLEM SOLVED. THE GUY AT THE SHOP   SAID IT SHOULD READ UP OVER 65.  

Answer
Ed,
 Sounds like there is some missunderstandings here.  He may be telling you to check the output of the stator but that can'r really be properly done w/o an ocilliscope.  This is not what you need to do yet.  Take your multimeter and temporaraly connect the test leads directly to the battery terminals.  At rest the battery should read 12-12.5 volts. (it may require you let it sit for a few hours to regain that voltage if it is being drained/not charged properly). Start the engine and check voltage.  At idle you should be reading 14-14.5 volts irregaurdless of RPM.  If this is so your charging system is ok.  If it is sufficiently below you may have one or more or 3 possible ills.  The voltage regulator may be shot.  This limits the voltage from your stator to 14.5 so you don't over charge your battery w/ too high voltage.  Second, your rectifier may be shot.  This is the circuit that converts the AC voltage your stator puts out over to DC in order to charge your battery.  If either of these fail your charging system will fail.  If you are reading above 15 volts while running you need to replace the regulator and you may have damaged your battery and rectifier.  If you recieve no or low voltage you may have a bad rectifier or a failing stator, again output must be checked at a well equipped shop.  You didn't tell me what kind of bike your dealing with so I'm not sure if swapping a regulator or rectifier is an option.  You need the proper bench equiptment to properly test them on there own.

Good luck,
Mike