Motorcycle Repair: Yamaha FJ1200sc Carbs/fuel pressure/Overflow, facet fuel pump, gravity fed

Question
I have a 1986 Yamaha FJ1200sc hooked up to an offroad minibuggy, I have a
Facet fuel pump hooked up to fit them, after a few seconds of running the
pump the carbs flood profusely, I tried to hook up a gravity fed line, but when
I hook up the fuel line they still flood out the overflow valve. Why is it
flooding? What fuel pressure can mikuni needle seats endure? I just installed
a a rebuild kit and gave em a good cleaning. Can these carbs hold up to fuel
pumps?

Answer
Did you replace the needles and seat in the carburetors? If not this would be a good place to start. I am unsure of the fuel pressure these carburetors can withstand. Either way, new needle and seat is always good.

                         Ride Safe,
                            Jerry