I recently lost my key and of course hot wired my quad, well the next day i found my key and when i grounded out the bike the day before to kill it something fried. I recently bought a used coil, ignition ,and I'm getting 12 volts to wire under coil, but no spark out. Some people say I could of fried the magnito, don't know how to test that. Could it just be another bad coil? It was ebay. It makes sense that 12 volts to coil & none out that its bad too... but could it be something else...

 

Remove plug cap and check if have spark from bare wire to the engine head,plus check wire for cuts/abrasions. Resistor caps can go out,plus could have wire problem.
If you are getting voltage to coil and cap good (5000 ohms resistance), check wire ends for continuity also, if wire is ok,then possibly coil is bad, but they don't go out frequently,usually some other problem. Try removing black wire connection from cdi and see if has fire. If does,then could be left control switch or cdi cut off problem.