Did a valve lash adjustment on my dad's John Deere LA140 lawn tractor. 13 years old and still running strong. Also changed out the main fuel hose and fuel filter. I've worked on this tractor so many times that it's pretty much an axe with three new blades and five new handles by now. But at 400 hours with no rust, good internal engine health (no oil burning and strong compression), and a rust free 48" deck, we'd rather keep this going than try our luck with any of the new riding mowers that seem to be built cheaper and cheaper by the minute.
One thing that surprised me is that even with this global supply chain disruption, Briggs and Stratton is still shifting more of their OEM parts production to China. The valve cover gaskets on these V-Twins used to be made here in the USA, but now they're made in China. Same with their ignition magneto wires and spark plug connectors. I'm imagining the whole engine's going to be made in China within the next few years if they keep this going, even if politics and a pandemic's wrath on the parts supply chain tells them they really ought to keep production in the US.