Hi Roberto, if you mean 8-9 litres, than that is way too much. My 250 consumes 3-3.5litres, but it was around 5-6, when I bought it. The 500s consume more, but according to fuelly it should 5-6 litres. Check sticky brakes, run a system cleaning additive and think about stripping and cleaning the carb, or if it is injected, get the throttle body and all the sensors, probably he injector too cleaned