> slightly lower RPM (2650), rough engine once airborne, black exhaust, a
> check of the engine parameters indicated a full throttle fuel flow of 47.5

with too much fuel one can see black smoke from incomplete combustion..
heck, remember your panel builder insisting that you need a dedicated switch
for high boost because if its turned on inflight, it can flood and stop
the motor? Remember the leaning process before takeoff at high DA airports?

I can get more fuel into my motor than can be burnt for most take-offs, because
its air limited (25"MAP) but once I get going with 32"MAP I want
enough gas to use all that air :-)

ie: @ 47.5ff, I hope you have more than 38"MAP... or more on these hot days.

Rob

ps: put extra N in that nose gear for OSH!