Note. According to the outer diameter, the pins are divided into three categories, each 0.004 mm. The category is indicated by a color mark on the end of the pin: blue mark - first category, green - second, red - third.
The mating of the piston pin and piston is checked by inserting the pin, previously lubricated with engine oil, into the hole of the piston boss. For correct mating, it is necessary that the piston pin enters the hole with a simple push of the thumb (Fig. 2-26) and does not fall out of the boss (Fig. 2-27), if the piston with the piston pin is held in a vertical position.
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Replace the pin that falls out of the boss with another of the next category. If the piston has a pin of the third category, then the piston with the pin is replaced.