If this is off topic, i apologize in advance. I am trying to jet a motor. its a four stroke twin with a single port intake manifold. 750 cc engine. I am using a 38 mm mikuni vm carb. this carb is not stock. Trust me, its not stock If any of this sounds remotely ignorant, please let me know. I am racing lawn mowers. we are required by the classes to use a mower engine no larger than 22 hp, and I have managed to acquire an 18 hp opposed twin briggs flathead. I built a custom intake, and have attached a single carb. my big challenge is to get the pilot jetting correct, and the needle/jet correct for my application. Does anyone have a clue what Im talking about, or is everyone sitting back giggling?