This seems to be normal as of now. Since u have started on complementary feeds, increase the quantity of water and not only after feeding , make sure he is given a small quantities in frequent intervals. There is no need for any calculated quantity.As it is summer now, insensible water loss will be more for children. In case if he persisting to cry get consolation from a nearby pediatrician.
Next Steps
More water
Health Tips
Maintaining adequate Hydration is very much beneficial in many aspects .
Gradually Try to increase more on complementary foods as much a u can. After 6 month weaned food should make a significant part of his diet.