16.1. The plugs should be removed with a puller - if they are sunk into the block, it will be impossible to get them out
2. Visually check for cracks, rust and corrosion. Check for stripped threads in the holes. It is a good idea to check the block for hidden cracks in a mechanical workshop with special equipment. If defects are found, the block must be repaired, if possible, or replaced.
3. Check the cylinder liners for burrs and scratches.
4. Measure the diameter of each cylinder at its top (just below the flange), in the center and at the bottom parallel to the crankshaft axis (see illustrations).
16.4a. Measure the diameter of each cylinder just below the flange (A), at the center (B) and at the bottom (C)
16.4b. The ability to determine the correct position of the telescopic gauge will come with time, so work slowly and repeat the measurement several times until you are sure it is correct
16.4s. To determine the diameter of the cylinder, the telescopic gauge is measured with a micrometer
5. Then, measure the diameter of each cylinder in the same three places, but across the crankshaft axis. Compare the measurement results with specification.
6. If you don't have the necessary precision measuring instruments, you can still determine the clearance between the piston and cylinder using a set of flat feeler gauges, although the measurements will be less accurate. A set of flat feeler gauges usually consists of 30 cm long feeler gauges of varying thickness and is sold in auto parts stores.
7. To check the clearance, select a flat feeler gauge and insert it into the cylinder along the piston installed in it. The piston should be installed in its normal position. The flat feeler gauge should be located between the piston and the cylinder on one of the thrust surfaces (at 90° to the piston pin hole).
8. The piston should slide along the cylinder (with the feeler gauge inserted) with moderate force.
(Information copied from the website: «MITSUBISHIMAN.ru»)
9. If it falls or slides too nenco, then the gap is too large and a new piston must be installed. If the piston is jammed at the bottom of the cylinder, and at the top of the cylinder it moves freely, then the cylinder is taper. If, when rotating the piston with a feeler gauge in the cylinder, positions are found in which the piston is jammed, then the cylinder is out of round.
10. Repeat the procedure for the remaining pistons and cylinders.
11. If the cylinder walls are heavily scratched or have ovality or taper exceeding the specification limit, the cylinders must be bored and honed in a specialized workshop. After boring, repair pistons and rings must be installed.
12. If the cylinders are in relatively good condition and not worn beyond the specified limit, and if the piston-to-cylinder clearance is within the norm, then there is no need to bore the cylinders. Only honing (section 17).