Yes there is dirt in the screen or nozzle itself ,remove and wash out dirt and reinstall .
Nestor's Ga. 770/410-9356
vincent nestor
Vincent Nestor
Nestor's Sprinklers & Lighting
Alpharetta,Ga.30022
vpn1@bellsouth.net
www.NestorsLandScape.com
www.GeorgiaLighting.net