Runs great and shifts great while riding during the day. At night with lights on plus led bar, it’s like the charging system can’t keep up. Replaced battery, rectifier, cleaned terminals and still doing the same. Unhooked the battery and pull started it, and the lights are working showing the stator is working. Any ideas?????

 

Charge the battery, and take it to get it load tested at advanced auto or auto zone, could be a bad replacement battery.

If nothing else and it is just not able to keep up with the load you are putting on it, you might need to upgrade the stator. Maybe here: Ricky Stator - Manufacturer of ATV and Dirt Bike Stators, Electrical Components, Lighting Systems and Suspension Products