I' d check the cam timing and the cable bushings. The bushings are on the top limb on either side of the idler wheel. They will wear out and start leaning diagonally and if real bad will split and lean severely.......either way you lose poundage. I have seen as much as 5 lbs just with bushings. Last time I had some replaced it was $ 5 . I had a friend with your problem on a MQ-32 and a couple twist of his cables and new bushings = 7 lbs . Hope that helps !!