650 - battery, neutral switch, side cover rubber, tach light
I have had problems with batteries in the 650. I got one bad one, the next was killed by the bike before I fixed the faulty charging system (installed SPARX), and the last battery was weak from day one. I decided to take my time and actually wait for a name brand battery to arrive via mail. I ended up getting a sealed YUASA battery. Hopefully I get more life out of this one.
I also replaced a worn out neutral switch. The internal spring was shot. This meant the neutral light was intermittent which was annoying. The new one is OEM but plastic! That was a surprise when the original one had a metal body. Hopefully the new one lasts as long as the original.
I also replaced a burned out tachometer backlight. The OEM bulb is 12v 3 watts which is hard to find locally. All I have found around here is 12v 5 watts.
Lastly I replaced some worn out rubber grommets that hold the left and right plastic side covers on.