Today I went to truck for setuping next Sunday race. First I tune engine. I introduce needle setting method. ① Main needle After warm up. On the bench trigger throttle max, after while engine sound changing high tone. The sound is coming from Fuel is not much provided. If sound not be changing main needle should tune clockwise. Depends on your truck straight length. You should adjust after how long after while by main needle. You don't continue trigger throttle after sound changing. If the truck has long straight takes 5 seconds on maximam,main needle should tune unclockwise. Until it takes 5 seconds to change sound. ②Secoundary needle After max sound changing you shoud operate full braking. Engine rotation will be down changing two steps. Max->High idling->Low idling. It is coming from secondary needle provide much fuel. Then should tune...