see what blade clearance is..prob 7-010.and see what leak is there.I set blade angle first and then bv to 28% on purple/black bvs and 25 on gray...bet we are in same ballpark setting at same blade angle cause as ya open blade up for idle leakdown increases.Hats need more bv because needs more fuel to cover stumble as they have a much bigger plenum..stacks less as they have virtually no plenum.