Those engines are good engines as long as they are maintained. You may be able to find a manual for the 450, which is the same engine for the most part relatively cheap. Good luck with it man, and I know exactly what you mean by opening it up. The only place I'd feel safe enough would be on an old fire road lol.
2008 700xx; Power Bomb header with power core 4 exhaust, Power Programmer III, pro armor nerfs, prm products control front and rear bumpers and full skid, 10" ITP rears, ITP Baja's fronts, RZR 2's all the way around, Uni filter, 13t sprocket, CCP steering Damper, DS450 shock swap, Dual Gasser Throttle, bar risers and Moose barkBusters. 730XX kit plus other engine mods!