If you have to perform maintenance tasks on your Hartford HD 125S then it will always be a great idea to have a Workshop Manual to use as reference in the event that you need to know tips on how to remove a certain component such as the Gearbox and fit it again the right way.
Hartford HD 125S Workshop Manuals offers you detailed diagnostic info for your vehicle so if something is wrong it can help you figure out what the situation is and tips to fix it. After that you can determine if this can be achieved on your own or if the job is too big you could make a reservation for your HD 125S right into a nearby car garage.
Hartford HD 125S manual