Greg,Hand burping the engine is basically to move the oil that has drained from the oil tank into the crankcase back into the oil tank. A crankcase full of oil on a dry sump engine is not good and harmful to the engine. Another plus is by rotating the prop slowly and stopping on the compression stroke of each piston you are forcing the oil back into the oil tank reassuring that the engine components are well lubricated prior to engine start. Spinning the engine over with the starter with a crancash full of oil can damage your engine.
