My last mower was a dual blade Toro with a B&S engine. The engine blew a head gasket after two seasons of mowing. Got that replaced under warranty and then it just wore itself out after the next couple of seasons. So only got 4 seasons out of it before it lost power and started using a lot of oil. Poor quality in my book. We do have an old rototiller with a B&S engine. That tiller is probably 40 years old and it always fires right up. So B&S used to build good stuff but I think they lost the recipe a few years back. I don't have any inside scoop, I just assume they went down the lowest cost vendor road and ended up with a lot of poor quality parts going into their engines.