Polini reinforced transmission cover, ideal for tuning above 70cc. The standard cover allows the gearshaft to sit in a recess and is only lubricated by the gearbox oil. This item has a ball bearing and needle bearing set up and massively reduces the amount of friction. The following bearings are fitted to the transmission cover: 6203 C4 (17x40x12) HK1412 (14x20x12) HK2216 (22x28x16) Suitable for horizontal Yamaha-Minarelli engines with long cases.