Regulator creep is a problem with deadheaded systems. The normal mode for the regulator is to be slightly cracked open at all times, letting just enough through to maintain pressure. When you lift, the regulator may go to low enough flow that it needs to close completly. Its not consistent at doing this. Its made worse by the fact that the differential pressure is high with Yaws recommended stuff. The pump is trying to stuff 7 psi into the back of the regulator, and the carb wants 2 psi (or less). Do some datalogging, and you'll find at times that you're building 5 psi at the carb if the regulator creeps. Then you start gently opening the throttle and find that the intake is full of raw fuel, takes a second to clear out, fouls plugs, people pass you exiting corners. The stock pumps and clicker pumps only put out a few psi, the differential is a lot less. Most of the clicker pumps can't supply enough fuel at high load though.