Motorcycle Repair: honda, honda cx 500, regulator rectifier

Question
hello,i have a 79 honda cx 500 delux.my problem is when i bought it,it started fine then the battery died,it was 3 years old so i bought a new battery,had the alternator checked "alt is good" but 2 days later the battery is dead again.my thoughts are the regulator rectifier,or bad wiring.i had a mechanic try a different regulator,rectifier but no change.the lights all work before and after it starts but are dim.i put it on trickle charge for about 4 hours took it off,it started twice fine then 2 hours later "dead".so now i dont know if the lights drain the batt while its running or if theres a short.any help would be greatly appreciated,thank you

Answer
Well, that's not normal.  First, make sure you have charged the battery over night on the trickle charger and then turn all the lights and rev the engine up to 3000 rpm or more and check the battery voltage.  If it's 13.5-14.5 volts, the alternator is doing it's job.  If not, the alternator is not putting out enough current.  Do you have any extra accessories like extra lights?  Is the brake light on all the time?  I've seen that drain a battery.  If the alternator is putting out the right amperage, you have something that is draining the battery.  Normally, the ignition switch disconnects the battery from the electrical system. If you have a volt meter that can measure current, measure if there's any current draw on the battery after the key switch is turned off.  If there is, you'll have to disconnect one circuit at a time until you figure out what's drawing the current.  I'd start with the regulator.

Good luck
Rich