YZ250F has only 1 pinch bolt. G has 2, H has 2 but are 43mm.
They sound like IT175J/K (82,83), IT200L (84) or IT250/465H/J (81,82) forks. Almost bet the farm.
As Nathan said they may be off a YZ125H/J but look at the bottom tripple clamp it has a recess for the radiaror water in/outlet.
Viper666