every motor and port design accent mods etc .gives it its own unique personality and air fuel requirments ,most builders know what to expect the settings to be at or atleats where and how their engines like fuel ,thats why picking the right company makes a big difference, without a personal touch you migth be left with an anemic bike that spits and sputters with no help from that big shops secretary or janitor who ansewers the 800 hotline