2.9.3. Dismantling and assembly

Dismantling. Take lock rings of a piston finger from the piston, take out a finger and disconnect a rod from the piston. Remove piston rings.
If some details of conrod and piston group are not damaged and a little worn-out, then they can be used again. Therefore when dismantling mark them further to collect group with the same details and to install in the former cylinder of the engine.

Fig. 2.37. Installation of a piston finger

Fig. 2.38. Check of landing of a piston finger

Assembly. Before assembly pick up a finger to the piston and a rod. At new details the class of openings under a finger in a rod and the piston has to be identical to a finger class. At the details which were in operation it is necessary for the correct interface that the piston finger oiled engine entered a piston opening from simple pressing of a thumb of a hand (fig. 2.37) and did not drop out of it if to hold the piston as shown in fig. 2.38.
Replace the dropping-out finger with another, the following category. If the finger of the third category was implanted into the piston, then replace the piston, a finger and a rod.
Oil engine flutes on the piston and piston rings and install rings on the piston. Focus piston rings so that the lock of the top compression ring settled down at an angle 30–45 ° to an axis of a piston finger, the lock of the lower compression ring — at an angle about 180 ° to an axis of the lock of the top compression ring, and the lock of an oil scraper ring — at an angle 30–45 ° to an axis of a piston finger between locks of compression rings.

Fig. 2.32. Sizes of piston rings

Establish the lower compression ring by bore down (see fig. 2.32). If on a ring the tag "Top" or "TORAHS" is put, then establish a ring by a tag up (to the piston bottom).
Before installation of an oil scraper ring check that the joint of a spring dilator settled down from outside, opposite to the ring lock.