I've heard that newer Briggs engines aren't what they used to be. That's sad because growing up my gokarts were powered either by Briggs or Tecumseh engines and I never killed one.
The Tecumseh engines that came in Ariens were unkillable. The Briggs motors I've had in my lawn mowers have been rock solid, and even the one in my snowblower runs like a swiss watch as long as it's not pouring it's oil out, but jesus.