Hi all, and thanks for accepting me to page. I have a little problem ( I hope) with my GTR230. On a recent ride all was well until accidentally venturing into shallow water. Some noise was evident as crap was sucked into pump. When deeper water was found, the ski vibrated badly and would not accelerate when throttle was squeezed, though at idle it sounded fine and traveled as normal at around 8kmh. Was able to limp back to boat ramp at a little above idle. Note there was no grinding noise from impeller section, only bad motor vibration when revved. Today I removed the IBR unit and found impeller to be in good condition with no real evidence of anything being stuck in there. I also removed the intake grate and inspected impeller with an endoscope and found all to be clear. I started engine briefly and visually checked impeller and shaft and all ran true. I'm starting to think the sand and crap through the jet pump may be a coincidence to the real problem and are now thinking it may be a misfire problem. Once again, at idle in the water all seems normal, bad vibes start when revs are increased. Any ideas?