Does anyone know what would cause one of my engines to pull back at 4000 rpms? She runs just fine a lower rpms but when I bring her up to 4000 she backs down and I also noticed that the engine shakes a bit. I have already checked both fuel filters (primary and secondary), all the lines for kinks and or loose fittings, switched the lines and even changed the spark plugs which did not look bad. I even removed, cleaned and swapped O2 sensors on the engines.<br /><br />The only thing that I notice to be different between the 2 engines is that my water flow gauge appears to be lower on the engine with the trouble although it seems to be pissing the same. Is there a sensor that monitors water flow and would it keep the engine from going over 4000 rpms if the flow was weaker that normal?<br /><br />Joe
