I have already did the ground modification.I have already replaced the rectifier.I have a new odyssey battery.When I start it up the voltage gradually goes up from 12 volts to about 13.80 then after a couple of revs it gradually goes back down to 12 volts.I shut it off and it wont start back it just spins,after it sits for about 10 minutes it starts right up without throttle.Now it wont even start,just spins.I check the spark plugs and very little spark and now no spark at all!What could it be?

 

Sounds like your scharging sytem is working just fine so your stator is more then likely fine.check coil your cdi only tells it to fire it has nothing to do with the amount of fire.