I found a manual for the 4200 series. Thanks to Simple John for putting it up in the Reference Library. The manual is circa 1983, and includes 8hp and 11hp with 36 in cut. It doesn't appear to cover the 4212, by the horsepower and deck width of the one I just purchased. It is close enough to give a lot of information about adjustments on belts and other pertinent information. I haven't located a parts list diagram yet, but perhaps I will find one yet.