Mix ammonia with a little water and try cycling that through the sprayer to clear any clogs inside. BIN gets chunky when it starts to dry, or when it comes into contact with straight water. If you cleaned the sprayer with only water and no ammonia that would cause the primer to solidify and form chunks inside that would definitely cause clogs. On my sprayers, which aren't handheld, you can take apart the gun and clean the parts, but I've never used those handheld sprayers, so I'm not sure if you can take them apart or not. There's probably an obstruction from the primer stuck inside that's restricting flow. Check your filter too if your sprayer has one. Those need to be checked and cleaned. You might want to also strain the primer before pouring it into the holding cup. BIN is a little gritty out of the can sometimes.