My CB500 has proved very reliable indeed. Last year the ignition switch failed, which I soon detected and after some fiddling, I could continue and make it home. Malfunction probably caused by me spraying WD-40 into the keyhole the month before, which had made a mess. Don't! These key switches do not require maintenance. Reliability had been compromised - also by me - some 40 years before, when I had fitted an inline fuel filter. Never again! Having the fuellines in the right length and diameter was enough to solve the problem. Petcock filter is still the same the bike had, when it left the assembly line. The only time in 40 years that I got stranded was in torrential rain. Plugcaps and/or HT leads got soaked. This is the CB500/550s true weak spot. Furthermore I recall a couple of main fuses blown and an overflowing carbbowl (2X) after hibernation, which was easily cured. As far as endurance, the CB500 will have its page in the history books, next to the pyramids.