Hello and my BMS Evo9 won't hold a charge!
 

Hey gang!

First time posting and I need help. I've had my 2009 BMS Evo 9 GY6 149.7cc for about 3 years. Been almost error free since I rode it off the lot back in California. Now after a repair here in Texas, including a brand new battery, it won't hold a charge. I've been warned about this joker here in the Dallas area and I shold have gone to someone else. But at this point I'd rather pop the cover and see what his mechanic did wrong.

This will be my first attempt at a repair, other than changing the oil and a few light bulbs, so all the gentle and simple advice you can give would be appreciated!

Thanks!

G-Man

First, welcome to the Forums. :D

If the battery isn't holding a charge, may have a bad battery, even if its new. Any Autoparts shop should have give a free testing.
If the battery is good, something might be grounded out, and killing it. Go over all wires, and check the ground clusters. They cheaply done.
Still dead, replace the Voltage Regulator. It is a small metal box attached to the triple tree, behind the headlight assembly, with a small cluster clip. Make sure it is bolted to the frame, it needs that ground point.
Finally, if needed, replace the Magneto..

That would be the order of operations I would take.

Sounds like good advice. This is my first attempt at wiring, and it's not a strong suite of mine. Is there a wiring diagram for the GY6 to let me know what's what, and what might be the culprit?

Thanks!

This is awesome! A great diagram!

Thanks!!!!