funny thing about the B5's......when the'ye in their sweet spot, and cold, the go past the "thump" spot kinda easily...almost seems like there is something wrong. BUT, let me tell ya...........there is nothing wrong and it will scream like crazy. i've got three B5's that i race with at the barn and wolcott and not a single one has ever failed me....even though the "turn over" rather easily............as long as the pinch is history, you're ready to go....just remember the BDC rule eash and every time you shut it down. and i ALWAYS stop my engines by pinching off the fuel line.........