If you have to undertake repairs for your AJS Eco 125 then it will always be recommended to have a Workshop Manual to use as personal reference in the event that you want to know the best way to take off a specific component including Drive Shaft and install it again correctly.
AJS Eco 125 Workshop Manuals provides particular diagnostic info on your automobile so if something is wrong it can help you ascertain what the situation is and tips to correct it. Then you are able to evaluate if this can be done yourself or in case the job is too big you can make a booking for your Eco 125 in to a decent repair garage.
AJS Eco 125 manual