My Sea Doo has been running fine, I was out for a ride and got too close to some rocks. It sucked up some rocks and I tried rocking it back and forth in the water and it still won't accelerate. I took it out of the water on my trailer and found 2 rocks stuck in the impeller area. I pry'ed them out and took off some fishing line while I was looking at the rod just past the impeller. Put it back in the water and it still won't accelerate. The impeller (4 prop fins) looked fine to me, no major dents or dings, minor stuff. What else can I check????