Dave, sorry I confused you. Yes, leak testing a BV is so you know how much fuel is going through the BV at idle. The percentage amount is a reference so if the car is rich or lean you can adjust the percentage up or down. The point I was trying to make is that a lot of tuners will tell people what percentage to set their BV at. You will see this a lot on this forum and other forums or at the track. Some will say set it at 83% some will say 78% some will say 85% and racers will go and set their percentage leak down to what they were told. The problem is that unless everyone uses the same reference and sets their BV the same way as to what lines are hooked up or not then they don't have the same reference. Being 2% or 3% off because the fuel lines were or were not hooked up can make a difference. If you are doing your own thing with your own tuneup then that percentage number is your reference and you can set it up anyway you want. I have always been told and use the standard of having the lines disonnected and the return capped off. If somebody tells you a percentage to set your BV at then ask if the fuel lines are on or off. The other thing that can confuse the leakdown numbers is the idle speed. The percentage leakdown with the BV and hat set at 2000 RPM is different to the percentage leank down with all set at 2700 rpm isle. If one is going to listen to other racers to get oneself started then talk apples and apples and not apples and oranges.