Worb5 crankshaft question

Hi again.

I have two little questions. I bought a  Racing crankshaft "Worb 5"Vespa PK125/ETS/N/XL/XL2, spec lip for reed-valve engines,24/25mm cone for my vespa pk125xl from 1889.So i saw in some forums i must put a new lightened flywheel if i don´t want break the crankshaft quickly.It´s that true? or i can use my original flywheel from piaggio?. Because  i bought it one year ago, it would be a same if i must change it.[:'(] But i don´t want to break the motor.[:S]

And my second question is about CDI ignition unit AddOnV some had problems with it. So its a good buy or not, could you give me your opinion and a little explanation were its is installed on the engine.


Thank you very  much indee for your attention.[:D]

Best regards.