I always liked the Tecumseh but the carbs are junk, they are a challenge to get running good.A 3hp Briggs can't compete with a Tecumseh speed wise, but that old Briggs will always start and run no matter how worn out it is. You are right, most of the original minibikes had Tecumseh's but some had Briggs engines too. My favorite engines now is a early 60s Briggs with the updraft carbs and oil bath air cleaners. I just bought one made in 1958 that hasn't run in years, after cleaning the points,carb and gas tank it fired up for the first time in years. almost on the first pull. But the hs40 i'm working on is giving me a hard time,tomorrow I will try the third carb on it and see it that helps it run any better.