I actually had the opposite problem with Leanne's bike - the pressure pump would not prime. I had to take the oil-pressure switch off and pump about a pint of ancient, aerated and unsteady oil through the sparkplug-less engine before it would accept oil from the tank. I'm glad I deleted the oil cooler from the bike - waiting for oil to return through another 6 or 7 feet of return line wouldn't have been helpful to the process. The carb's needle and seat were perfect, the only ones I ever noticed that a minor 1 or 2" vacuum would hold the floats up, and yet still something cocked the needle and the bike hosed me down and deposited a large pool of raw fuel on the floor. It worked thereafter...
Leanne was telling me about a defect in Evo or Twincam that, in the middle of a ride, can allow the crankcase to fill with oil and blow out every seam and the breather, all over the rider's legs etc, and yet, it can be fixed on the side of the road. I am having touble imagining what that might be...heard of anything like that?