Clean the crankshaft, especially flush the oil passages with pressure oil, blow dry with high-pressure air (or air pump), and do not leave yarn hair when wiping.

Clean the main Bare Engine, and clean and blow dry all the oil passages of the cylinder block like the crankshaft. Install the bearing on the Bare Engine, apply engine oil, put the crankshaft into the person, close the bearing cover, and tighten the nut until the upper and lower bearings are closed.

Tighten the main bearing nut, starting from the middle bearing, and tighten it crosswise to both ends in turn. The two nuts of each bearing cover should be tightened crosswise several times, and the crankshaft should be shaken at any time to check the tightness until the nut reaches the specified torque. If it is too tight, it should be removed and repaired, and a scraper should be used.

First install a cylinder on the Isuzu Engine, then surround the piston with an iron ring and gently push it in with a hammer handle.

At the same time, turn the crankshaft to near the top dead center so that the connecting rod big end is accurately installed and sits on the connecting rod shaft. Push the piston to turn the flywheel so that the connecting rod big end and the connecting rod journal rotate together to the position where the Bare Engine is installed.

During the rotation process, the connecting rod big end should not be separated from the connecting rod journal to prevent the tile from falling off the crankcase. Install the Isuzu Engine, tighten the connecting rod bolts as required, rotate the flywheel, check whether the crankshaft rotates flexibly, and then install the fuse and cut off the excess. Never leave the wire head in the oil pan.