54 Comet. So can a damaged oil quill cause a seizure? The oil hole in the main shaft was bodged, closed up so that the quill could not easily be pushed in, not sure what happened there, bike is new to me, (hammered?) The damaged oil hole wore off some of the flat threads where the quill enters the main shaft. Piston seized while about 20 km into a ride, was going a steady 60 mph at the time, bike never went over 65. There was plenty of oil, when I took the cylinder off there was oil on the cylinder below the piston, squirted oil through the intake lifter hole, and it comes out the oil hole in the cylinder. The rubber thingys in the timing case looked OK, no blockage detected when I removed the oil feed screw with the jet. Checked ignition timing, it was close, maybe a few degrees retarded. Plug looked fine, nice tan color, no deposits that shouldn't be there. The professional mechanics I showed the piston all say lack of oil. I can't see how the quill damage will starve the Timing case, given that it is down stream, from the TC, and the end of the quill was not damaged, unless the whole thing was worn down. I guess I will have to wait for the new one to compare the two.