I have the stock rad. and stock impeller on my FST 840 with no issues runs between 190-215. I also run evans coolant.
08' Teryx LE, FST 840, Muzzys, VDI, Dalton, VFJ Roller, Thunderhawk Performance Race Cage, Bumpers, Door Bars and Bracing, Beard TSX Seats, 5pt. Crow Harness, 12" ITP Type 7 Beadlocks, GBC 8 ply Dirt Commanders, Pro Armor Skids, Team Green Plastic
08' Teryx, Maier Orange Plastic, Thuderhawk Performance 4 Seat Cage, Bumpers, Door Bars and Bracing, Beard TSX Seats, 4 pt. Harness, 14" Chrome Doughas Diablos w/GBC Grim Reapers, VDI, Dalton