These connecting rod bushings, also called piston pin bearings, are located in the upper part of the connecting rod where the piston pin passes through.
They will need to be replaced at virtually every overhaul of the engine; if the piston pin can be pushed through the bushing with a light thumb pressure, replacement is not necessary, but in most cases it will not be necessary.
After the old bushing is removed, the new bushing is pushed in, and then the operations that still have to be carried out begin. Drill the holes in the oil channel and grind the inside until the piston pin can be pushed through the bushing with a slight thumb pressure.
Useful information from Paruzzi magazine and from our YouTube channel :
Look for more technical articles on the page Paruzzi Magazine