Motorcycle Repair: cb750sc electrical, battery voltage, rectifier

Question
my 82 cb750sc will not charge the battery when running. i surmize that it is the rectifier. My 2nd issue is that the left ignition coil is putting out a charge to the plugs, but i can hole the wire and get a mile shock. the coil that powers the right 2 cyl if i do this it knocks my socks off.  the right 2 cyl hit and run very good. the left 2 are not. summary, the spark is not hot enough on the left 2.  question: is the coil weak or what is keeping it from putting out a hot spark. i thought they would either work or not.   tks Mike

Answer
Sounds like you have a few issues with the bike.  First I would check that the alternator is getting current, without current it cannot generate current.  Then check the output, you can check battery voltage it should go to close to 14V when the bike is revved above 2000 rpm.  If the coil still works but is weak, then the coil may indeed be the problem.  Easiest test is to switch out the coils and see if the problem switches with the coil.  Good luck,  Jan