Clean the Bare Engine, especially flush the oil channel with pressure oil, blow it clean with high-pressure air (or air pump), and do not leave yarn hair when wiping.

Clean the main bearing seat, clean and blow the cylinder body of the Cummins Engine. Install the bearing seat, apply oil, close the bearing cover, tighten the nut, and close the upper and lower bearings.

Tighten the main bearing nuts, cross from the middle bearing to both ends. The two nuts of each bearing cover should be tightened crosswise several times, and the Cummins Engine should be shaken at any time to check the tightening degree until the nut reaches the specified torque.

If it is too tight, it should be disassembled and checked, and repaired with a scraper; all main bearing nuts should be tightened to the standard torque, and the Bare Engine should rotate evenly and flexibly.

When installing the Bare Engine, the upper and lower spindle tiles cannot be replaced with each other, the upper shaft tile must have an oil hole, and the ports of the upper and lower tiles should be on the same side. The oil groove on the thrust plate should face outward, and the oil seal lip should face the oil direction.