04-08-2020, 08:59 AM
It's been so many years since 1963/64 that I only remember doing the checking, but not the specifics. Remember, these were industrial engines, not true racing engines. They had ordinary workers building the engines, not Italian craftsmen. Most engines never saw 10,000 RPM, let alone 13K. The 7, 8 and 9 were not boost port engines, and weren't nearly as quick as a Mc90 or 91. They were saw motors sold as kart motors. I believe McCulloch deserves great credit for doing as well as they did, turning industrial engines into racing engines for a crowd of folks who, for the most part, were not tech trained racers, but grocers, doctors and bus drivers. The engines had amazing durability! Ted