I am looking for some suggestion I have a 58 Viking with 1200 HP Mans. I burnt out 2 sets of Michigan props (cavitation) 31 x 46 4 BL I am now running a set of Kutapult 30 x 46 5BL which after 100 HR appear to to have cavitation burn and I lost 2 Kts although they run smother. Has any one found a cure for this problem with out losing speed