Like fishfiles was saying, if your rpm settings are out of whack, it's usually something wrong or it's been messed with.
A thing I noticed--If someone pulls the steering panel, when the throttle lever is removed, there is a bracket with stop/set screws that goes over the lever. I always mark the front of the bracket so I re-intall in the correct orientation. If it is intalled backwards, this will throw your settings off. The stop/set screws are for the hand lever, so if they are stopping the lever before the throttle lever on the engine hits the stop, it could be simply that the bracket on the hand lever is backwards.
Unless you have a G-series with a Deluxe Panel that displays rpm, the only safe way I have found to measure rpm is with a phototach, and a piece of tape on the flywheel. Safe for me , anyway, I was to askeert to reach in with a spin-tach with the belts and stuff.
I want one of those tachs that has a transducer that clips onto the injection line.