Saturday: Decided to replace battery. Old battery has only been in the bike a year and a half. but it refused to start the bike once and was barely able to get bike started another time, although fully charged. I am keeping this battery as a backup and a way to power my strobe. Pulled side cover off, carefully removed all the wires (in addition to the many wires that go to battery, I have a pigtail to plug a charger into) tied all the ones that go to the positive terminal together and all the ones that go to the negative terminal together, eased old battery out, eased new battery in (there is NO battery clearance on a Mark III) connected all the negative wires up and connected all the positive wires up. Positioned piece of truck innertube over battery to avoid accidentally touching frame, strapped battery down and buttoned everything up.
Then went over bike with a cleaning rag and chain lube, checked a decent assortment of bolts and made sure there was oil in the primary case and in the gearbox. I check engine oil everytime I come back from a ride. Finally, plugged in new battery to the charger. The charger display was wonky. I tried a second charger, same thing. Considered options, decided it was not going to get better with age and took the seat and the side cover off. Found that despite all care, the negative ground of the pigtail had slipped away when I was removing wires. Bolted pigtail wire to battery and replaced the seat and side cover a second time. This time the charger display looked like it should and I left the bike to fully charge while I got some lunch.
Sunday: Chilly but sunny. Layers, riding suit and helmet on, bike out of garage, hit starter button, Norton fires right up and sounds good and off to a pleasant 97 mile loop on twisty country roads.
Happy New Year, all