Well you don't have allot of time left but if you where seeing them well and now your not than I'm guessing it might have to do with pre-spawning and not just for the pike but for there food source like perch and other small fish. I would stay with the weeds for sure but maybe move a little closer to shore or follow the drop off that your on about 60 yards away. I don't know how the Pike travel in your lake but I do know that in the lakes around me 20 yards can make a huge difference, like this year my shanty's where only about 50 yards away from each other and one of them out did the other by a ton.