I'm really only replying because I seldom hear of a KLR with as many miles as mine. We're about even, at 95,000 miles/153,000 km.

I carry a diaphragm for the fuel petcock (with a rebuild kit) on my KLR. Never used it, but it's easy enough to carry. I've also taken to carrying two clutch cables following a series of failures. One stays zip-tied to the cable in use; the other rides at the bottom of a pannier. A spare tube (or two) is a no-brainer, and I bring fork seals and wheel bearings because I've got them. Sizes on the latter are pretty standardized, and failures aren't sudden, so carrying them isn't really crucial...but I once spent two days looking for fork seals in Bulgaria, so I learned my lesson.

Some other stuff I carry just to save the trouble of thinking about it or searching when I'd rather be sleeping late: oil filters, a pre-oiled air filter, a spark plug, and about twenty thousand nuts, bolts, washers, pins, circlips and other such. Oh, and a few valve cores: they go bad, you know.

That second chain thing sounds like a royal pain. I just buy another one a couple of thousand miles before I think I'll need it, then wait. They don't need adjusting for thousands of miles, and cleaning consists of spritzing with WD-40, then wiping with a rag if I happen to feel like it. They last 15,000 miles/25,000 km; why switch it out when a couple of spins of each nut adjusts it just fine?

I used to talc my tubes, until a mechanic pointed out to me that "talc" is really just cornstarch these days. Ever notice what cornstarch does when you mix it with watery gravy? That explained why whenever I patched a tube in the rain or after a river crossing it was always all gooey.

YMMV.

Mark

Edit to add: I looked at oldbmw's post again. If I want to change out a chain I need to loosen (i.e., un-adjust) it and pull my axle, or remove a link. Is that really worth doing before the chain wears out one or two continents later?