60's burn about one ounce per minute wide open. Ten ounces, ten minutes. Your 75 will burn slightly more. Count on 8 1/2 minutes wide open. You can stretch that a bit with power management. Often by several minutes. Touch and goes give great mileage. The smallest tank I use with a 60 is 12 ounces. I would suggest at least 12 or 14 ounces for a 75.