Well, it's also possible that he got to the end of his gearing. From my experience, I don't think a 250 Maico would've fared much better once it comes time to race a car in 5th. After getting used to my Husky and it's 6th gear (which is actually an overdrive!) the AW250 felt... well... slow. There's lots of horsepower left over, but the thing runs out of RPM. That might be the case in this video. Or, it just might be out of horsepower.