I recently purchased a Wagner Power Painter model 317E (110 Watts). I've run about three gallons through it so far (all latex, but thinned appropriately). It's been extremely frustrating to use, though, as the piston seizes in the cylinder every five minutes or so and I have to disassemble and clean the unit to get it running again.
I clean the unit very well after each use, and have put it away oiled and ready to go each time. I've tried the 1.5 quart paint container and the larger backpack, but get the same seizing behavior with both.
I've heard that the pison will seize if the sprayer encounters air bubbles in the paint, but I've been careful to stir the paint gently and keep the paint level well above the suction tube.
Has anyone had the same problem with their sprayer? Any suggestions on how to get it to spray without seizing?