Visually check:
- condition of connecting rods (twisting and bending);
- the cleanliness of the bearing surfaces of the cover and the crank head of the connecting rod.
Use a 1500W heating plate.
Place the upper connecting rod heads on the tile.
Make sure the upper ends of the connecting rods are in full contact with the tile.
Place on each connecting rod head (as temperature indicator) a piece of tin solder at the point indicated by the arrow in the figure, where the melting point is approximately 250°C.
Heat the top ends of the connecting rods until the solder melts.