When my mechanic changed the handle bars, for some unknown reason it created a front brake problem. When the bike is off, I have full brake. As soon as I move it, or start it, I have absolutely no brake unless I pump it 3 or 4 times, then have full brake again. We have bled the lines, changed master cylinder, lines, calipers, re-bled, re-bled and re-bled, to no avail. I asked online experts, who suggested my rotor was warped, but that isn't the case. I've had two mechanics trying to figure it out and they're absolutely stumped, especially because I can have full brake, hold the lever in, and when I start it, lose the brake. Any suggestions? I rode out to Sturgis this way. A little tricky on Needles!