im not sure what your asking,,,, a gpr whether they have plates/grates or not will always walk from side to side at certain speeds usually when coming onto plane ........ is that what your talking about?
I think what he is talking about is when you either take off from a dead stop or Idle or maybe you are crusing at about 15-20 mph and nail it, the engine sounds pretty much right on, but the feel of the bike, it feels like its slipping or not grabbing the water not propeling the bike any where as fast as it should...
Then something will happens, be it you cut the handle bars back and fourth, hit smooth spot on the waer, a different water plane angle, etc.. etc... and it feels like it grabs, then your off and running like a raped Ape....
Last time I was out on mine I thought I was feeling this too, but I could not figure out how to explain very well to my bud that fixes our waverunners...
When I finally get him to see/understand me, we were pretty much done for the day, it was dark and everyone was pulling out...