http://chineseatvperformance.blogspo...red-asian.html
there are tons of upgrades you can do to the 150cc gy6 engine that comes on most automatic f-n-r utility style chinese quads now a days. you can really open the thing up. its the engine style from a scooter, like those scooters they driev in foreign countries and stuff you see. so you can get plenty of upgrades, tips, and such on any scooter website. i basically did almost everything the guy talks about in the site i posted above. oh and yes you do feel a difference, and its customizable to the way you like to ride based on the wieghts in the variator and the springs in the clutch. go for it, ive basically upgraded everything but the carburetor because theres no point in getting a bigger carb if the intake on the head is still the same size. if you were to bore it out then i would go bigger on the carb. so hope this helps.
http://www.chinariders.net/images/sm...cons_tmbs1.gif