I did this boost port mod to my stock cylinder and piston, and HOLY #¤&#¤&#¤& did she run after that

! It has almost no bottom end, weak middle, but top end is nothing less than insane! This easily lets ur engine rev ALOT higher, so much infact that I dont dare to use that engine to often.. I havent measured the revs, but from the sound of it, I would say this mod threw on 3-4K rpm over stock..atleast..and atleast double power over stock through the rpm gains!!!
A funny story is that I at first thought I had completely wrecked the cylinder from doing this mod, because of the lowlow bottom end, and then it suddenly sort of "kicked in" when it got some revs, and boy did it kick in too, u should have seen the grin on my face..

With a proper racing pipe, and adjustable clutch this little engine truly can kick ***!