I just repaired a twist that crashed because the engine died in a down-line at the complete wrong time. Now that I have the plane back together again I want to make sure that it doesn't happen again so I added a small fuel filter thinking that the additional volume of fuel in the line will help, but while testing on the ground, the plane will only run for about 10 seconds with the nose down. Is this normal or should I expect more time than that? Any thoughts on how to keep the engine going during long nose down maneuvers?

Thanks,
schu