Oh, hey! I didn't see that you had responded.
On the XP--When I run flat out on smooth water, the ski runs great all day long.
If i fill the tank and start jumping waves, it runs great for about an hour, then when it hits about 3/4 tank, It will lose power seconds after landing a big jump. Then I have to reprime it and let it run on smooth water until the fuel system gets the air bubble out, and it runs like crap until then. Probably running lean also, i don't know.
I am guessing that as the fuel sloshes around in the tank on jumps, it is letting air into SOMETHING when the fuel level gets a bit lower than full. There is no fuel leak anywhere else in the system, so I am left to think that the fuel pickup is sucking air and depressurizing the fuel system when I roughhouse on it.