Just got my Titan 510 from totally wicked and its a vapor beast but! every 5 or so puffs i have to top up because the vapor becomes somewhat less and almost flavorless. when pulling out the cartridge stuffer i can see that 90% of the fluid is still in the cart *just standard stock cart filler nothing i did myself* so im wondering if this is normal? or is there anything i can do to improve it, maybe a tube mod is absolutely necessary for this model? any ideas much appreciated 