I have just checked the cg on my stock Pursuit with an Aquastar 3974-2200kv motor fitted & Seaking 180 esc,the esc is on one side of the boat behind the motor. 2 Gens Ace 3s 5000mah weighing 370g each are in the centre on the stock battery tray ( batteries pulled almost to the motor) & i have 30% cog. If i push the batteries a bit more forward just under the deck i get 32% cog.