2. Push the piston rings into the grooves (see illustration). Using a feeler gauge, set the clearance between the ring surface and the groove surface in the piston. If the gap is more than 0.15 mm, then the ring or piston is worn.
12.2 Measuring the piston ring gap in the piston grooves
3. Next, in order, insert all piston rings starting from the top of the sleeve. To measure the piston ring lock gap, insert a feeler gauge into the gap between both ends of the ring. Piston rings that have too much lock clearance cannot be installed again.
4. To determine the clearance of the working surface of the cylinder, measure the diameter of the hole. The hole must be measured in the longitudinal and transverse directions and at three sleeve depths. In this way, the largest and smallest diameters are found. Write down the values. Now subtract the piston diameter from the bore diameter. The measurement takes place in the right corner with respect to the piston pin bore. The difference is the cylinder clearance, which should be in the range of 0.023 - 0.047 mm. If the cylinder clearance is larger, install a new liner.
5. Check piston pins and bores for wear or damage.
6. Using a special tool, check the connecting rods for deformation, since bent or twisted rods do not contribute to the trouble-free operation of the engine.