big deck seems to no feed or multifeed erratically. have replaced feed tires, feed clutches(2 on back of drawer), torq limiter. previous tech had affixed weight to upper pick up roller. Customer runs a coated matte stock, approx 70#. any tips on optimizing feed on this deck? it seems to work ok with other stock, but customer needs to run this. havent tried cassettes, due to capacity/ size of job.