If you have to execute fixes on your Honda C90 K3 then it is always recommended to own a Workshop Manual for a reference if perhaps you need to know how you can remove a certain part for instance the Exhaust and install it again successfully.
Honda C90 K3 Workshop Manuals gives you particular diagnostic wisdom for the automobile therefore if something is wrong it can help you determine what the issue is and the best way to resolve it. After that you can evaluate if this can be done on your own or if the job is too big you can actually make a reservation for your C90 K3 in with a decent friendly mechanic.
Honda C90 K3 manual