Clymer Repair Manual XR50/CRF50 & XR70/CRF70 Clymer Repair Manual for Honda XR50 & XR70. Clymer manuals are written specifically for the do-it-yourselfer. Manufacturer manuals are purposely designed for the professional technician. These provide easy-to-follow instructions that allow the novice or less than proficient user to safely and efficiently service and repair his machine. Extremely useful to have when attempting to rebuild your engine or put a bore kit on!