I posted the other thread about the bogging problem. I pulled the powerhead off today. There is a cast aluminum plate about 3 or 4" thick that the powerhead sits on. Is this the exhaust tuner? I put a straight edge across it, and there was a good size gap on the wall between the exhaust port and water jacket. I pulled the plate (exhaust tuner?) off, and under it looks like a white plastic seal on the water passage that is chipped up. I'm sure these parts aren't sealing, and water is being sucked in. Do you think this could be causing my problems?<br />Thanks again for any help and advice!<br />Tim