Why worry? Let the representative of Yamaha do everything himself. The pump drive breaks down, this happens in the Roadstar series. To replace it, you need to remove both clutch baskets - that is, the right part of the primary gear. Underneath is an oil pump drive. They will also change nut and its washer of clutch hub. And that’s all. All work under the clutch cover. There is no need to disassemble the engine.