If you need to do fixes on your Yamaha YZF 600 S Thundercat then it will always be a good plan to possess a Workshop Manual to keep just for reference if perhaps you want to know the right way to take out a certain part much like the Gearbox and fit it again in the right way.
Yamaha YZF 600 S Thundercat Workshop Manuals provides distinct diagnostic wisdom on your vehicle so if something is playing up it helps you work out what the issue is and how to resolve it. Then you are able to evaluate if this can be done by yourself or in case the job is simply too big you could make a reservation for your YZF 600 S Thundercat in to a suitable garage.
Yamaha YZF 600 S Thundercat manual