2015 sportsman etx wont start

Please help!!
I have a 2015 sportsman etx. Has about 12hrs of ride time on it. Running fine when I parked it. Sat in garage about 3-4 months. Tried to start it, battery was dead. Charged battery, still wouldnt start. At this point i have drained gas, new battery, new plug, cleaned injectors, and changed in tank fuel pump. It’s firing and fuel is reaching injector. I am not an experienced mechanic.
Please help