i had this problem on thursday.
what the problem (for me at least) was that on the test stand it would be a little rich. however when throttled for takeoff the forward movement of the plane would lean it out just enough to kill it.
richen it a little and see if that helps.
is that FP a airbleed carb? if so turning it in does richen it.
if it is a regular (dual needle) carb turning it out will richen it