All honda 250r factory hubs are 25 and will not work, I have a few sets laying around.
honda 24 spline hubs  will work if they are slightly worn and or the axle is. If both sets of splines are in factory they will not slide in and will require some beating, heating or some form of fiddling. I have oem new honda 400ex hubs and they do not slide into a 24 splindle suz axle. 24 spline honda hubs ive test were 450r,400ex (both add width) and 200x hubs that are flat.
Yamaha hubs that I tried that were 24 spline and fit were banshee, yfz450, raptors, warriors. All flat. Yfz 450r fit and add width.