I have had the same problem with Yamaha brakes with YZ250 -00, YZ450F -03, YZ250F -07 and YZ450F -08 (I had all these bikes from new). The brakes both feel spongy _and_ there seems to be little friction between the pad and the rotor no matter how much I bleed them(it makes a difference, but in the end they are still not good). My dad's CRF450Rs, on the other hand, (-05 and -07) had/have an extremely firm feel at the lever and the pads lock to the rotor to the point of grabbiness. On the 250F I tried Honda Pads and EBC MX-S pads, and that somewhat helped the friction issue, but the lever feel is still slightly mushy. The stock pads on my 450 seem ok (they should be the same as the 250 but somehow they seemed to grab a little better). So, I asked my father (since he says he never uses the front brake) if I could try and switch the master cylinders. He said it was ok so I did it. Instant Honda feel at the lever, WHOOHOO! Now the question is, why does Yamaha use the crap master cylinder(both Yamaha and Honda use Nissin)? Do they like have a warehouse full of them? I will still install the MX-S pads and hope to have true one-finger stopping power, not just a sort of deceleration.