How do you check cdi box for 50cc scooter?

take the cdi box off and try cranking the scooter youll notice that it still sounds like the coil is bad then wait till night time plug the cdi back up then watch the coil if it throws a spark its not your cdi it might be your spark plug but if you see no spark then its most likley your cdi box or coil thats teh best way to know if your scooter is cdi enabled or needs a coil theres a big defrence when it comes to price of these devices though.