The Yost Pro Power Tube for Mikuni, by design, produces a very fine mist. This allows the fuel to stay in suspension longer for better control of air and fuel mixtures and can be almost perfectly matched for any throttle position. You can expect an increase of up to five H.P., improved mid range performance, and an incredible throttle response. Comes complete with 165, 170, 175, 180, and 185 main jets, rubber washer and the Yost Float Bowl Drain Nut. The main jets in this kit are interchangeable with stock H-D CV main jets. Consequently, they are not interchangeable with Mikuni jets. The jet threads are different, even though the actual size of the jets are the same. So when you have a 175 Mikuni main jet installed then use the supplied 175 main jet from this kit.