Yamaha part number LIT-19616-A0-37 is the factory service manual that covers this car, and the 2021 UMAX RALLY 2+2 EFI carries the model code YUM2A21_UMAXCG. Check that code against the plate on your car before ordering; it is the surest way to know you have the right book.
Rather than issue a separate manual for each season, Yamaha wrote one volume for the 2020 through 2023 UMAX range. Alongside the RALLY 2+2 EFI, the same book documents the UMAX 1 EFI, UMAX 1 RALLY EFI, UMAX 2 EFI, UMAX 2 POWERTECH AC, UMAX 2 RALLY AC, UMAX 2 RALLY EFI, UMAX BISTRO EFI and UMAX RALLY 2+2 AC. Where a system differs between those cars the text says so, so you follow the path that matches yours.
This is the same reference a Yamaha golf car dealer works from: removal and installation sequences, adjustment values, torque figures, wiring diagrams and the diagnostic routines used when something will not run right.
