If you wish to do repairs for your Yamaha FZ 6 then it will always be recommended to have access to a Workshop Manual to use as personal reference in the event you need to know simple methods to remove a particular component like the Gearbox and fit it again safely.
Yamaha FZ 6 Workshop Manuals will provide you with special diagnostic wisdom with regards to your vehicle so if something is playing up it will help you determine what the problem is and the way to repair it. After that you can assess if this can be done yourself or in case the job is too big you can still make a reservation for your FZ 6 right into a nearby friendly mechanic.
Yamaha FZ 6 manual