The amount of people enquiring at parts departments in the UK for advise on how to choose what colour shell bearings to fit became a problem at our dealership. The parts people didn't know and couldn't advise anyone on what to fit. Not much was known about them at the time. People were relying on workshop manuals for guidance and Honda were not being truthful on how to select them. They wanted owners to go to a dealership and have them do the job. I knew the trick of how to work out the colours required, one of the Honda trainers passed it onto me. So in the end I was always the mechanic they were told to ask for by the parts department. I was happy to help them out. In the 70s owners did far more maintenance than today, so yes Honda would have that in mind, hence why they made it so difficult to understand the process.
If you look at the markings on Honda fuel lines for instance you can see they are only rated to withstand 10 parts Ethanol and that's the stuff Honda are still providing to this day. Orings are made of nitrile not viton, so even if they matched the same spec as the fuel line they'll fail after the content goes beyond E10. Seals MAY last a little longer but I doubt it, technology in the 70s wasn't that advanced, certainly not to the point they'd be planning for large amounts of Ethanol in fuel. They were still using leaded petrol back then, remember when they were unsure of how valve seats would withstand unleaded fuel, no forward planning at all.
Honda weren't alone in doing this, all of the Japanese manufacturers did it. They never imagined a bike lasting for this amount of time so why future proof them, it costs more and thus they earn less profit.
