Boy, it seems like it would really be a good idea to know where the debris came from or what exactly it is... without knowing, would always have a concern there could be more.... someplace else in the engine ? Keep an eye on oil pressure and check for more debris ! I have electronic ignition on 2157, it's the new laser optic unit. Can't remember the brand name, i could look it up though. Points, condensors and timing are a pain in the ass. Ok once set up, but still require maintenance. For a rider, as trouble free as the CB750 is, a rider deserves electronic ignition, imho. Actually, name of ignition system is C5. I bought directly from family owned business who ditributes the C5. GREAT personal service and support,