Since I don't have any additional tool box storage places on my bike, The stock kit is it. I'm not even sure what's in it.
Things I have had fail out "there." A sunken carb float--my favorite--on a Matchless with an Amal. I had sufficient tools to take the float bowl off, I think I had a little piece of tape to seal the float for awhile. It got me about 80 miles to home. Of course, the tape fell off! It was a slow leak.
Flat tires. I used to carry a plug kit when I had tubeless tires. They don't work worth a crap on tubes! I usually ride slowly on the flat to a gas station and and proceed to solve the problem from there.
Ignition problems. I have a G5. What the hell am I supposed to do out in the sticks? Ain't gonna reset the points or worry about finding TDC. A spare spark plug cap? Ya gotta be s%&*ting me.
Cables. A throttle cable should be obvious before it totally fails. Clutch cable. I've ridden many miles without a clutch cable. Up shifts are easy, downshift require a blip of throttle blip to do them smoothly. To stop shift into neutral. To start push off with your feet to get it rolling, then drop it into first. Choke cable, who uses it? They are nice things to have at home, but I never felt the need to carry any of them with.
Broken chain, Probably not a bad idea to have a spare master link, but that will fit in the tool box. May even be one in there. Guess I oughta look.
There are three spare fuses in the fuse boxes. Shouldn't need any more.
Bulbs. Got spares at home. Don't do much night riding. Should survive. Probably rattle apart carrying them around anyway.
Bare
Bare