I have had a very similar problem before on a X-2 with a BN44. First time I left the ski in our storage build at the lake. I came back a week later and the carb and crank was full of gas. The second time was this past week, I noticed gas and oil in the hull after a ride. Once I got home and put the ski outside I looked in the hull and found pure premix right under the return line. I believe the leaky return line was fixed with a worm gear clamp instead of a zip tie. I have never figured out why my carb and cylinders filled up though.
Does anyone put a fuel cutoff on the x-2?