Hey guys.

I have a problem with this waverunner wr500 1993 I just bought. The previous owner told me that it has just been fully rebuilt which seems to be true. I did a compression check and it was 145/145. Carby is rebuilt and clean. At home when I run it on the tap it is like a new ski, good throttle response, good idle (as seen in video 4) but as soon as the rear of the ski goes under it won't run.
Here are some videos of it.
Vid 1

Vid 2

Vid 3

vid 4

Has anyone experienced this problem. Any help would be appreciated.