There are two screens to clean, one on the bottom of the tank and the other is on the transfer pump on the back side of the engine. Also it might pay to check the electric pump by cracking the line where it arrives at the engine with the key on to see if it is pumping all the way up. Another idea is the next time it dies, stop everything and check for fuel flow by taking off the bowl on the bottom of the tank. This could tell you if something is in the tank. A friend of mine found a ball of tape in their 7720 when it was new this way. Hope this helps.