I will buy a gilera runner (old shape). The one i want to buy has: DR Evo 70cc Yasuni r Dellorto 19mm Malossi MHR variator Malossi sponge Polini reeds When I will get it I will change the crankshaft and bearings. Should i also change the carb for a 17.5mm? Is there a big difference in fuel consumption and performance? I want to change the exhaust because of police. I will get the original exhaust and carb with the bike. Is the stock exhaust good enough and what is the original carb size on the old gilera runner? I read that the yasuni r is not much better than the cheaper exhausts (zx,tt...) with a 70cc sport kit. Is that true? What is the fuel consumption with a 19mm carb and 70cc sport kit?