When I cleaned my carbs I couldn't find split pins for the choke linkage arms, so I just straightened a paper clip, cut in pieces and used them in place of the split pins. Later I bought them from Honda -ouch, a little later I bought a set of different sizes for about 4 euros-, and keep then stored for when the next carb disassembly comes. It may be never, and maybe when I need them I won't remember where they are...