Its loaded on youtube and search with: KX250 crank seal leak test. It goes for about 20 secs. Motor is pumped up to 5-6 psi although it will leak almost immediately. I sprayed detergent/water mix on the seal and as you can see the leak is severe. Motor is now in the shop getting a new wiseco crank/bearings/seals (crank rebuild is the same cost as a new non OEM crank ) after I stripped it to the point of splitting the case. This saves labour costs. Oh yeah the bird noises in the background are pet rainbow lorikeets! I'll stop now as I seem to be running this thread, just passing this info on.
YouTube - KX250 Crank Seal Leak Test