I had the same problem with my Infiniti in my Syclone, but it wasn't actually the fuel arm...The screws that hold the carb into the block don't clamp down on the carb, but rather are threaded into the carb...The easiest way to fix this is to seal it up with a little permatex around the threads and heads. I don't know if I did it wrong or used too much, but I had the stuff stiffened up inside the carb body restricting air flow. I ended up going with the 2 needle carb off the taiwan engine, and couldn't be happier...I just had to tap out those holes and put bigger set-screws.