Yamaha aerox 100 not charging

Hi I need help I’ve got a 2000 aerox 100 Cc
Runs and rides perfectly starts first kick but won’t charge the battery or work the lights
I’m guessing it’s the stator but can’t find one anywhere for the 100 Cc all the ones en eBay and other places seem to be for 50s and have 3 wires this one has 4 in the plug that goes to cod
Please help

 

Could be the reg/rec.
Isn't it a vertical minerelli motor in those?

 

Grab a multimeter, Set the meter to VOLTS, put the probes across the battery terminals, read the meter. You should get a reading of battery voltage around 12v.
Start the bike and let it idle. Read the meter again. It should be around 13.6v or slightly more.
Rev the bike to 5000rpm, read the meter. If no change, the stator is shot.
But it could also be the connections so check those for cleanliness first.

This is the Yamaha part number for the stator:
4VP-H1403-00