CDI only working with my NiMH not my 2s LiPo?!

[GRK963]

So, just got my savage octane out of the garage to start it up and after it failing to start I checked the spark and the LiPo I always used for the CDI won't power the CDI anymore... But my NiMH I used for the servo does. The LiPo does power the servos fine though. Charged the LiPo to full and the charger says it's at 8.2V. anyone know why this is happening?