Looking through that website shows you can spend over $100 pretty easy.
The question is, Why would you want to when you can go to Harbor Freight and get a 212cc for $99. More than twice the tq and hp
of the 79 cc. JMO
I know Cars and Cameras tried putting on a header pipe, drilled the carb jet and modified the air filter/box. It didn't do much and they soon pulled the engine and put on a 212.
Danford1