that is a nice kart engine not variated just a regular kart clutch im sure it puts out well over 10 hp that would make a ped friggen scream
i had a lauson kart engine kind of like that 100cc 15hp at about 15000 rpm i had it on a custom built stand up scoot it was just crazy fast nuts and i had another one and put it on my cousins gokart and it went like 80 and that was an untuned engine with no exhaust on it just picture it with an expansion chamber and tuned
the old macs were the best
they dont make engines like those anymore all we have today is crap