I have just recently bought a 1993 Chris Craft Concept with a 454 330hp (model 744CPEJUB) OMC king Cobra drive. The motor has recently been rebuilt and bored 0.030". The boat should run 46mph @4700RPM (14 1/2" X 19 pitch) and I can't get it to rev higher than 3800RPM and 35mph with that prop.<br /><br />I have had a mechanic check the carb, gears in the outdrive, compression, changed cap, rotor, plugs and wires. I can install a lower pitch prop and my holeshot is better and RPM higher but my top speed is still only 35mph.<br />While checking the drive, I noticed the boat was in salt water, which the previous owner didn't mention.<br /><br />Other than the lack of RPM, the motor idles great and there is no backfiring . It just doesn't have the power it should. I'm out of ideas and the boating season is coming to an end here in Northern Ontario.<br /><br />Could it be that the wrong cam was installed when the motor was rebuilt?<br /><br /> 
