Reply To: Non-start (no fuel pump prime)-new owner – 2018 Gt650r
13.5v is the lowest acceptable limit , but caution to upgrade the regulator in the future. Don’t buy knock off aliexpress ones please, they WILL fry the bike!
Though , you can still get yourself another OEM one at your local dealer , if you want to keep it original , personally i use Shingden Japan regs (what you see on the shop) , then again , Shingden gets a LOT of fakes online too but that’s a whole other conversation as I am digressing sorry.
Bike seems OK from what you said, so go have fun 🙂