BREAKAGE OF ROCKER ARMS: This is a rare occurrence, usually happens under racing conditions, with very high rpm, and/or high lift cams, increased valve spring strength, insufficient spring clearance at maximum lift, etc. However, it did happen, but rarely, on stock early Airheads, in non-racing use, and only in the /7 era, as far as I know. If you look closely at a rocker arm, immediately next to where the ADJUSTOR screws into the rocker arm, the web width there on the suspect rocker arms is about 7 mm wide. BMW made a production change and the rockers with the factory change had a 11 mm width. There was no change in the rocker part number. It does not appear to be a formal re-call by the Factory. I am not listing all the rocker part numbers, except two, because: 1. No new rockers are available that are 7 mm. 2. It is easy to confuse yourself over the SEVERAL part numbers used for the rockers. The original part numbers, long gone now, were 11-33-1-262-403 and -404. 3. You can measure your rockers.