The Y16ZR uses a Deltabox frame (similar to the R15). The manual covers:
Yamaha Motor Corporation sells digital access to service manuals via their Yamaha Technical Center (Y-Tech) or authorized resellers like Cyclepedia or RepairManual.com. yamaha y16zr service manual pdf
Many underbone forums (e.g., Yamaha T135, 2WheelsThailand, or Facebook groups) host links to scanned or leaked copies. While you can find the manual here, the quality varies. The Y16ZR uses a Deltabox frame (similar to the R15)