While some of the problem seems alleviated by altering line #330 in the Cadet.air file to 1 instead of 0 and making the same change in the aircraft.cfg file under propeller type (from 0 to 1) and by altering the "gear_reduction_ratio" from 2.3 to 1.25 as Stringbean suggested, the overall effect remains unsatisfactory.
With those changes made, I was unable to sustain the 800'/min climb rate at 70 MPH, and at 1000feet altitude. I only achieved the 120 MPH advertised cruise speed with the throttle wide open pinned on the red line.
After changing the "gear_reduction_ratio" again, this time from 1.25 to 1.50, I was able to sustain a climb at 500'/min. to 1000' at a speed of 80MPH. Straight and level at 1000', the Cadet cruised at 121 MPH with the throttle wide open at 3200 RPM, well in excess of the 2600 RPM red line.
The design author of the Culver Cadet is Dan Cowan. He has done a few aircraft for MS sims, most recently a version of the Icon A5 uploaded to this site in July of 2009. The A5 claims to be for FSX, but it flies very nicely in FS9. Problem is Mr. Cowen didn't attach an e-mail address to his "read me" file so the only addresses that I've been able to find are so old they quickly bounce back.
After trying for almost two years to correct the problems associated with the Cadet, I think there are only two ways this aircraft is ever going to fly properly.
1.) Someone out there has an address for Mr. Cowan and, under the circumstances, is willing to contact him to advise that someone is trying to correct an error in his model, or
2.) Some aircraft designer still working in FS9 takes Mr. Cowan's basic work and creates a new model file, aircraft.cfg file and cadet.air file that accurately models the aircraft.
The Cadet is a great little aircraft designed by Al Mooney. It is the precursor to the Mooney (M-18) Mite that Tim Conrad made for FSX. The looks of the FS9 Cadet are spot on. They are not to fancy, but they are representative of how the actual plane looked as WW II ended. It would be a shame not to find a solution to the problems that plague this FS9 model