starting/charging problem on an 84 750

on my 84 interceptor 750 my battery keeps going dead after 2-3 starts regardless of if i ride it or not between starts. i had the battery tested and its still good, ive gone though my manual to check the charging system. my stator is good, the voltage output is good. my main concern is my rectifier/voltage regulator because it failed the continuity test that my manual had but the voltage regulator still passed in terms of limiting the output to less than 15 volts to the battery. ive tried checking the amp output like my manual tells me but it wants me to remove the main fuse while the bike is running and hook up an ammeter in series. problem with that is my bike dies when i remove the main fuse. any thoughts or suggestions?