1. CYLINDER HEAD BOLT HOLE SLIPPING OR DAMAGEDTHIS SITUATION IS CAUSED BY EXCESSIVE FORCE OR POUNDING WHEN TIGHTENING THE CYLINDER HEAD NUT. IF THERE ARE INDIVIDUAL THREADED HOLES THAT SLIP, THEY CAN BE RE THREADED AND A CYLINDER HEAD BOLT THAT MATCHES THE THREADED HOLE CAN BE MACHINED. IF THE WIRE HOLE IS DAMAGED OR MULTIPLE WIRE HOLES SLIP, IT CANNOT BE REPAIRED.2. FREEZE CRACKINGTHIS IS THE MOST COMMON DAMAGE TO DIESEL ENGINES IN WINTER. CRACKS IN THE BODY CAN ONLY BE REPAIRED BY COLD WELDING IN AREAS THAT ARE NOT UNDER STRESS. FIRST, DRILL CRACK STOPPING HOLES AT BOTH ENDS OF THE CRACK, THEN PLANT SEVERAL IRON NAILS ALONG THE CRACK, AND THEN ADD SEVERAL PLATES PERPENDICULAR TO THE CRACK DIRECTION. USE LOW-CARBON STEEL WELDING RODS TO WELD FIRMLY ALONG THE CRACK AND THE PLATE. PAY ATTENTION TO LIGHTLY TAPPING THE WELD SEAM WITH A SMALL HAMMER WHILE WELDING, AND THEN USE FLAME CORRECTION AFTER ALL WELDING IS COMPLETED.3. TRACHOMAFIRST, USE A STEEL WIRE CONE TO ENLARGE THE HOLE, THEN PLUG IT WITH ALUMINUM WIRE OR USE SPOT WELDING TO PLUG IT.4. THE 205 BEARING HOLES ON THE UPPER AND LOWER BALANCE SHAFT ENDS ARE WORN.THIS SITUATION MUST BE REPAIRED IMMEDIATELY. WHEN THE WEAR OF THE BEARING HOLE IS LIGHT, THE 205 BEARING OUTER CIRCLE METHOD CAN BE USED TO REPAIR IT. USE OXYGEN WELDING TO SYMMETRICALLY POINT THE STEEL WIRE AT A SMALL POINT ON THE OUTER RING OF THE BEARING, CORRECT IT WITH A FILE, AND THEN PRESS IT INTO THE BEARING HOLE FOR USE.ANOTHER METHOD IS TO USE A 2MM THICK IRON PLATE TO MAKE A LARGE FLAT PAD WITH AN INNER HOLE OF 50MM, AND MAKE THREE SCREW HOLES ON THE FLAT PAD AND THE MACHINE BODY, AND FIX IT WITH FLAT HEAD SCREWS. WHEN THE BEARING HOLE IS SEVERELY WORN, THE ORIGINAL HOLE CAN BE ENLARGED AND FITTED WITH A SLEEVE, AND THREE SMALL SCREW HOLES CAN BE MADE AT THE JOINT BETWEEN THE FITTED SLEEVE AND THE MACHINE BODY, AND FIXED WITH SCREWS.