If you need to do adjustments for your KTM 300 MXC USA then it is usually recommended to have access to a Workshop Manual for a reference just in case you need to know how to strip off a specific part such as the Gearbox and fit it again in the correct way.
KTM 300 MXC USA Workshop Manuals provide you with particular diagnostic information for the automobile so if something is wrong it can help you ascertain what the problem is and ways to repair it. After that you can decide if you can do this by yourself or in case the job is just too big you can actually book your 300 MXC USA in to a local car garage.
KTM 300 MXC USA manual