EVERYTHING. at home i have every tool imaginable for just about everything. for the road ive got 2 craftsman toolboxes filled with i think a 300 piece craftsman tool set. i also carry a grinder, drill, drill bits, propane torch, hammer, zip ties, flywheel puller, easy outs, wire cutters, mity vac and so on.
i also have pre cut pieces of chain in case i need to change gearing to something oddball and it wont fit what im running at the time. got about 2 of every front sprocket from 12 to 18. got at least one of every rear and 2 of most of them (40, 41, 42, 44). masterlinks, tons of jets, a huge assortment of nuts and bolts, spark plugs, jbweld..
i carry gas, oil, tranny oil, hand cleaner, wd40, brake fluid, a couple gallons of water, a couple gallons of anitfreeze.