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Depending on the unit/brand you choose , you should not need a flywheel , just the stator kit , however , some kits require a battery of some sort and a regulator/rectifier , or a battery and a regulator , to run the lights , depending on the output and/or type of lighting used , such as LED or Halogen , turn signals , brake light , horn , etc. .... it all makes a difference on what is needed ...
I do not have the setup , so can't say firsthand , but the general consensus is , the type of kit you buy will determine what exactly is needed in addition to the stator itself , if at all .....