I've had one apart a couple of times on Pandora -- an 03 Gen 1.The first time the switch failed, I was hundreds of miles from home on a weekend after all Yamaha dealers were closed. I had one or two "warning shots" -- turned the key on, nothing happened, turned it off and on again and the bike came to life. But after a couple of those, it failed completely. This was sometime in 2005, IIRC.
Step 1 is getting the damn thing out, which is a problem because they used special security screws that are torqued until the hex head snaps off on installation, leaving a smooth rounded top. I used a borrowed dremel tool to cut some slots in the remaining bit of the heads so I could wind them out with a screwdriver.
There are two sets of contacts, one for the ECU (IIRC) and the second for the rest of the bike. The second was heavily pitted from arcing. I cleaned it up and swapped the contacts around so the undamaged contacts carried the heavier load. When I got home, I applied Kopr-Shield to the contacts to prevent future arcing. I reinstalled with regular machine screws to permit future service.
That lasted many years, but eventually I started having the "warning shots" on another trip in 2021. I took it apart and found the same problem developing again. By now, Yamaha had redesigned the unit and I bought one of the new ones -- part number 90891-30058. As shown in the article linked above, the new switch has more contacts to distribute the load. It came with two new security screws with instructions to drill out the old ones. I threw those away. It also came with two new keys. I swapped my old cylinder in and threw away the new keys and cylinder too.
But sorry, no You-tube of my adventures.
