To discover exactly which parts you require use the on-line schematic exploded diagram - it will even give you some idea of where and how to fit those new parts.
The Yamaha XT660R 2005 3S61 EUROPE 1D3S6-300E1 has forty-six Other parts fiches.
forty-six Yamaha XT660R 2005 3S61 EUROPE 1D3S6-300E1 parts fiche schematic pages.