My factory float levels were all over the place when I checked mine a few years ago,
The other problem I had that coils 1 and 3 (both rears) stopped working and I ordered a few more sets off pinwall for about $29 each set of 4, so I have spares now, not sure why Yamaha
Made the rears so exposed the the elements under the bike like that.
So anyways when I changed them out all was good for me.
Same symptoms as yours.
Good lunch with what you find.
Note:: both rears are cyl 1 and 3
And over the years goose figured out that it's really not the coil itself
It's the wire that you can not change out, bench testing doesn't really seem
To work that we'll from what I have noticed on these forums .
Jeff