I tried to start my motorcycle and out of the blue the battery was completely dead. I had it running the day before. I disconnected the neg cable and fully charged the battery. I went to connect the cable back up and got lots of sparks. Do you have any ideas. My brother said it might be the magneto.

The battery is most likely the problem. Once you get her started , remove the negative battery cable . It should stay running . If it dies then the charging system has an issue.

how did you disconnect the battery, pos first then neg ? or neg first then pos ? try starting it and after started, hold your rpm at 1500, for about two minutes, then if still running, drive it to get to.speeds of 40 for about 15 minutes, this is to relearn if not, disconnect your battery, take the pos and neg cable and touch them together and hold for about a minute, then Connect them back, neg.first.then pos, then follow steps above to.relearn.

have the battery load tested fir bad cell

Do not disconnect the positive Or negative cable while vehicle is running it is no longer an acceptable test and damage to computers could occur as there is no ability to suppress or absorb a voltage spike. If you remove the negative cable to check for an amperage draw that's an other thing. You should use a meter and connect it in series between the neg post and the neg cable once all modules are in sleep mode there should be no more than .3v as a rule of thumb. If more you have a parasitic draw which you could isolate the system/circuit by removing fuses one at a time. When the draw is gone that's the circuit in question.

I think you need to study about:

Closed or Completed Circuits
Open Circuits
Short Circuits

NO ONE has any idea what a short circuit is

If you had one, you would have a blown
fuse or burned up something

a short most likley in the alternater have someone check the hot post on it for ground with the cable off there should be none

If it was an alternator related problem the car would die while it was running. it could still be a bad battery. i have gotten a few new batteries that were bad.

try this:
-drive the car for about 15 mins to make sure the battery has a good charge
-after you park it, then disconnect the (-) neg cable from the battery
-let the car sit over night with the battery disconnected
-the next day hook the (-) neg cable back up to the battery and try to start the car

if the battery is good, it will start normally
if its bad you'll get the -no start- problem

If the battery is good, you have a parasitic drain some where in you electrical system.

Well you killed the electrical power to the bike when you disconnected the cable yes that suppose to happen as for the regulator possible.
but have the regulator and the stator checked to see if is burned or grounded.

If the battery is fully charged there is but one thing tjst gives you those symtoms. You simply have a bad connection at the negativbattery cable. It won't hurt to ck the positive cable also. This os a common thing when a battery is connected and idle..Always disconnect the bat neg if the the vwhicle won't be used for more than two days. If possible, don't charge your dead battery with the alternator of the vehicle. It could very possibly cause charging problems. The clickinf is from insufficient voltage and jump stating with te dead battery still in place doesnt work because the goog and bad batteries are try to balance again, causing low voltage/amps to the starter. Good Luck. Sorry about the lesson, habit.