If you wish to perform repairs on your own Yamaha XT 660 X then it will always be a good idea to own a Workshop Manual for reference in the event that you want to know simple methods to take out a certain component much like the Gearbox and install it again appropriately.
Yamaha XT 660 X Workshop Manuals offers you distinct diagnostic guides for your car or truck so if something is wrong it helps you understand what the situation is and the way to repair it. You can then analyse if this can be done on your own or that the job is just too big you can still book your XT 660 X into a suitable garage.
Yamaha XT 660 X manual