Certain engines, all short-stroke, were prone to this problem, which nothing obvious seemed to cure, and for no obvious reason either. Gauzes were fitted to problem engines across the inlet stub and the transfer ports. The late Tom Wess had a 1928 Flying Squirrel that was totally original, with the engine untouched from new. I watched as Tim Sharpe opened it up, and the gauzes were intact but blocked by a layer of long-dead mixed insects, bits of straw, and feathers…
