Heres a good one. 2556 cierra Bayliner with I/O cobra outdrive , 5.7L engine. Ran about thirty miles the other day with out a glitch. Turned around to head back and it seams I cannot get full speed. Runs great at idle and in nuetral if I apply power gradually. But if I hit the throttle to full fuel it starts sputtering even in nuetral. Normally cruise at 3800 but now can only get 3300. Replaced all plugs/wires/distributor/fuel pump/re-built carb/pulled main fuel line off the tank and ran it in my kicker tank to rule out a suction problem. Changed filter in carb during carb rebuild. Noticed engine coolant down about 2 qts. Compession test reveals two cylinders a bit lower than others. They were about 130 compared to 150 on the rest. Keep in mind this is a 1998 engine with 250 hrs. I suspect maybe coolant leaking into a cylinder when the engine heats up and is under load. Is there any other way to check for this before I pull the heads? I did pull all the plugs and look for signs of rust or a miss firing plug. I did not see anything that just jumped out at me. Please help any ideas would be appreaciated. I am Mechanically inclined but I seam to be drawing a blank at this point.<br />Thanks<br />Dan