I have a I/O 2000 7.4L MPI sterndrive. I have a rather loud squeel between 2250-4000 RPM. I changed the belt, tightened the idler, listened with a mechanics stethoscope, but cant seem to find the source. The squeal is loud enough to hear with the engine compartment closed but pretty loud with it open.
Everything spins free with the belt off. Also, curiously, the noise is only there when the prop is engaged and the boat is moving forward. If I rev it up in neutral to 2000-4000 rpm, no noise. I dont understand how it can be there when the engine is turning the prop, but not when its idle. RPM's are RPM's right? If the alternator was doing it, would it matter if the engine was under load or not? how would the alternator or power steering know?
Everything spins free with the belt off. Also, curiously, the noise is only there when the prop is engaged and the boat is moving forward. If I rev it up in neutral to 2000-4000 rpm, no noise. I dont understand how it can be there when the engine is turning the prop, but not when its idle. RPM's are RPM's right? If the alternator was doing it, would it matter if the engine was under load or not? how would the alternator or power steering know?