Yes, that was Foureasy, he made his with an Athena giordoni jug with a 45mm bore and built his own pipe welding every tiny bend into place.... the finished product made just over 8 hp and pushed his 24" bike over 45mph with awesome acceleration.
Then thrre was another guy on youtube that used a cast iron Minarelli jug connected to the case with a 1/2" thick steel plate that looked like he just cut out with a torch and a longer rod but i dont remember which rod he used, but his was putting out 14hp and spun at around 13k rpm, the bike was hitting 60 mph in short blasts on the dirt rooster tailing like a kx80 in low gear. I got a pm from Mrfubbs a while back with a link to the jug this guy used and a close up pic of the engine. I truly never thought a stock ChinaDoll clutch could hold that kind of power.... I'll have to find the youtube link and post his too... this one ya gotta see to believe ....