I tried pods on mine and found just the same happening. The pods have less air resistance to were reducing the vacuum level in the velocity chamber so on idle, drew less fuel. I tried to install restriction plates in the pods but then the top end was affected. Fine balance these bloody things. Went back to standard and all good again. Don't give up though, you do need different jets in the carbs to use pods or low resistance exhausts. Again ,fine balance and every bike will be different dependant on the combination. Also assuming the carbs are balanced and no blockages in thee idle jet under the butterfly.