Okay, I got it running again pretty good with the Walbro WT 391, 11mm carb. and the blue colored diaphram seems to be okay with the nitro since I have run it a few times and it is pumping consistantly at high rpm (with the spring in the pump) it seems. Did not use any washers between the carb and manifold since they were keeping too much of a space. I am keeping the high needle rich. I needed to put some pieces of fuel tubing between the head of the needles and the springs to keep them tight. Anyone else ever have to do this to keep the needles from backing out?