If you choose to accomplish repairs on your own Yamaha WF 450 F then it will always be recommended to have access to a Workshop Manual to keep just for a guide if perhaps you want to know tips to take off a specific component such as the Gearbox and match it again correctly.
Yamaha WF 450 F Workshop Manuals will give particular diagnostic information for your automobile therefore if something is playing up it helps you work out what the problem is and how to fix it. You will be able to determine if you can do this yourself or if the job is just too big you can book your WF 450 F right into a trusted garage.
Yamaha WF 450 F manual