You have to keep in mind the PP engines and to some extent Westbends were just a generic engine much like a Briggs back in the day .They used them on just about any thing,water pumps,generators ,lawn mowers etc .They produced more power to weight ratio than a 4 cycle making them more portable .Those old slow speed engines are just about like boat motors,they can run almost for ever . They became obsolete and became banished to the barn for a couple of decades .Saws get resurrected and ran on occasion but certainly not on a daily basis .